Tag Archives: laboratories


Turning the Oregon Outdoor Market into a Research Opportunity

By Dr. Zacariah Hildenbrand, Dr. Kevin A. Schug
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Much has been made about the plummeting market value of cannabis grown outdoors in Oregon. This certainly isn’t a reflection of the product quality within the marketplace, but more closely attributable to the oversaturation of producers in this space. This phenomenon has similarities to that of ‘Tulip Mania’ within the Dutch Golden Age, whereby tulip bulbs were highly coveted assets one day, and almost worthless the next. During times like these, it is very easy for industry professionals to become disheartened; however, from a scientific perspective, this current era in Oregon represents a tremendous opportunity for discovery and fundamental research.

Dr. Zacariah Hildenbrand
Dr. Zacariah Hildenbrand, chief technical officer at Inform Environmental.

As we have mentioned in previous presentations and commentaries, our research group is interested in exploring the breadth of chemical constituents expressed in cannabis to discover novel molecules, to ultimately develop targeted therapies for a wide range of illnesses. Intrinsically, this research has significant societal implications, in addition to the potential financial benefits that can result from scientific discovery and the development of intellectual property. While conducting our experiments out of Arlington, Texas, where the study of cannabis is highly restricted, we have resorted to the closet genetic relative of cannabis, hops (Humulus lupulus), as a surrogate model of many of our experiments (Leghissa et al., 2018a). In doing so, we have developed a number of unique methods for the characterization of various cannabinoids and their metabolites (Leghissa et al., 2018b; Leghissa et al., 2018c). These experiments have been interesting and insightful; however, they pale in comparison to the research that could be done if we had unimpeded access to diverse strains of cannabis, as are present in Oregon. For example, gas chromatography-vacuum ultraviolet spectroscopy (GC-VUV) is a relatively new tool that has recently been proven to be an analytical powerhouse for the differentiation of various classes of terpene molecules (Qiu et al., 2017). In Arlington, TX, we have three such GC-VUV instruments at our disposal, more than any other research institution in the world, but we do not have access to appropriate samples for application of this technology. Similarly, on-line supercritical fluid extraction – supercritical fluid chromatography – mass spectrometry (SFE-SFC-MS) is another capability currently almost unique to our research group. Such an instrument exhibits extreme sensitivity, supports in situ extraction and analysis, and has a wide application range for potential determination of terpenes, cannabinoids, pesticides and other chemical compounds of interest on a single analytical platform. Efforts are needed to explore the power and use of this technology, but they are impeded based on current regulations.

Dr Kevin Schug
Dr. Kevin A. Schug, Professor and the Shimadzu Distinguished Professor of Analytical Chemistry in the Department of Chemistry and Biochemistry at The University of Texas at Arlington (UTA)

Circling back, let’s consider the opportunities that lie within the abundance of available outdoor-grown cannabis in Oregon. Cannabis is extremely responsive to environmental conditions (i.e., lighting, water quality, nutrients, exposure to pest, etc.) with respect to cannabinoid and terpene expression. As such, outdoor-grown cannabis, despite the reduced market value, is incredibly unique from indoor-grown cannabis in terms of the spectrum of light to which it is exposed. Indoor lighting technologies have come a long way; full-spectrum LED systems can closely emulate the spectral distribution of photon usage in plants, also known as the McCree curve. Nonetheless, this is emulation and nothing is ever quite like the real thing (i.e., the Sun). This is to say that indoor lighting can certainly produce highly potent cannabis, which exhibits an incredibly robust cannabinoid/terpene profile; however, one also has to imagine that such lighting technologies are still missing numerous spectral wavelengths that, in a nascent field of study, could be triggering the expression of unknown molecules with unknown physiological functions in the human body. Herein lies the opportunity. If we can tap into the inherently collaborative nature of the cannabis industry, we can start analyzing unique plants, having been grown in unique environments, using unique instruments in a facilitative setting, to ultimately discover the medicine of the future. Who is with us?


Leghissa A, Hildenbrand ZL, Foss FW, Schug KA. Determination of cannabinoids from a surrogate hops matrix using multiple reaction monitoring gas chromatography with triple quadrupole mass spectrometry. J Sep Sci 2018a; 41: 459-468.

Leghissa A, Hildenbrand ZL, Schug KA. Determination of the metabolites of Δ9-Tetrahydrocannabinol using multiple reaction monitoring gas chromatography – triple quadrapole – mass spectrometry. Separation Science Plus 2018b; 1: 43-47.

Leghissa A, Smuts J, Changling Q, Hildenbrand ZL, Schug KA. Detection of cannabinoids and cannabinoid metabolites using gas chromatography-vacuum ultraviolet spectroscopy. Separation Science Plus 2018c; 1: 37-42.

Qiu C, Smuts J, Schug KA. Analysis of terpenes and turpentines using gas chromatography with vacuum ultraviolet detection. J Sep Sci 2017; 40: 869-877.

Swetha Kaul, PhD

Colorado vs. California: Two Different Approaches to Mold Testing in Cannabis

By Swetha Kaul, PhD
Swetha Kaul, PhD

Across the country, there is a patchwork of regulatory requirements that vary from state to state. Regulations focus on limiting microbial impurities (such as mold) present in cannabis in order for consumers to receive a safe product. When cultivators in Colorado and Nevada submit their cannabis product to laboratories for testing, they are striving to meet total yeast and mold count (TYMC) requirements.In a nascent industry, it is prudent for state regulators to reference specific testing methodologies so that an industry standard can be established.

TYMC refers to the number of colony forming units present per gram (CFU/g) of cannabis material tested. CFU is a method of quantifying and reporting the amount of live yeast or mold present in the cannabis material being tested. This number is determined by plating the sample, which involves spreading the sample evenly in a container like a petri dish, followed by an incubation period, which provides the ideal conditions for yeast and mold to grow and multiply. If the yeast and mold cells are efficiently distributed on a plate, it is assumed that each live cell will give rise to a single colony. Each colony produces a visible spot on the plate and this represents a single CFU. Counting the numbers of CFU gives an accurate estimate on the number of viable cells in the sample.

The plate count methodology for TYMC is standardized and widely accepted in a variety of industries including the food, cosmetic and pharmaceutical industries. The FDA has published guidelines that specify limits on total yeast and mold counts ranging from 10 to 100,000 CFU/g. In cannabis testing, a TYMC count of 10,000 is commonly used. TYMC is also approved by the AOAC for testing a variety of products, such as food and cosmetics, for yeast and mold. It is a fairly easy technique to perform requiring minimal training, and the overall cost tends to be relatively low. It can be utilized to differentiate between dead and live cells, since only viable living cells produce colonies.

Petri dish containing the fungus Aspergillus flavus
Petri dish containing the fungus Aspergillus flavus.
Photo courtesy of USDA ARS & Peggy Greb.

There is a 24 to 48-hour incubation period associated with TYMC and this impedes speed of testing. Depending on the microbial levels in a sample, additional dilution of a cannabis sample being tested may be required in order to count the cells accurately. TYMC is not species-specific, allowing this method to cover a broad range of yeast and molds, including those that are not considered harmful. Studies conducted on cannabis products have identified several harmful species of yeast and mold, including Cryptococcus, Mucor, Aspergillus, Penicillium and Botrytis Cinerea. Non-pathogenic molds have also been shown to be a source of allergic hypersensitivity reactions. The ability of TYMC to detect only viable living cells from such a broad range of yeast and mold species may be considered an advantage in the newly emerging cannabis industry.

After California voted to legalize recreational marijuana, state regulatory agencies began exploring different cannabis testing methods to implement in order to ensure clean cannabis for the large influx of consumers.

Unlike Colorado, California is considering a different route and the recently released emergency regulations require testing for specific species of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus). While Aspergillus can also be cultured and plated, it is difficult to differentiate morphological characteristics of each species on a plate and the risk of misidentification is high. Therefore, positive identification would require the use of DNA-based methods such as polymerase chain reaction testing, also known as PCR. PCR is a molecular biology technique that can detect species-specific strains of mold that are considered harmful through the amplification and analysis of DNA sequences present in cannabis. The standard PCR testing method can be divided into four steps:

  1. The double stranded DNA in the cannabis sample is denatured by heat. This refers to splitting the double strand into single strands.
  2. Primers, which are short single-stranded DNA sequences, are added to align with the corresponding section of the DNA. These primers can be directly or indirectly labeled with fluorescence.
  3. DNA polymerase is introduced to extend the sequence, which results in two copies of the original double stranded DNA. DNA polymerases are enzymes that create DNA molecules by assembling nucleotides, the building blocks of DNA.
  4. Once the double stranded DNA is created, the intensity of the resulting fluorescence signal can uncover the presence of specific species of harmful Aspergillus mold, such as fumigatus.

These steps can be repeated several times to amplify a very small amount of DNA in a sample. The primers will only bind to the corresponding sequence of DNA that matches that primer and this allows PCR to be very specific.

PCR testing is used in a wide variety of applications
PCR testing is used in a wide variety of applications
Photo courtesy of USDA ARS & Peggy Greb.

PCR is a very sensitive and selective method with many applications. However, the instrumentation utilized can be very expensive, which would increase the overall cost of a compliance test. The high sensitivity of the method for the target DNA means that there are possibilities for a false positive. This has implications in the cannabis industry where samples that test positive for yeast and mold may need to go through a remediation process to kill the microbial impurities. These remediated samples may still fail a PCR-based microbial test due to the presence of the DNA. Another issue with the high selectivity of this method is that other species of potentially harmful yeast and mold would not even be detected. PCR is a technique that requires skill and training to perform and this, in turn, adds to the high overall cost of the test.

Both TYMC and PCR have associated advantages and disadvantages and it is important to take into account the cost, speed, selectivity, and sensitivity of each method. The differences between the two methodologies would lead to a large disparity in testing standards amongst labs in different states. In a nascent industry, it is prudent for state regulators to reference specific testing methodologies so that an industry standard can be established.


Emerald Conference Showcases Research, Innovation in Cannabis

By Aaron G. Biros
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Last week, the 4th annual Emerald Conference brought attendees from around the world to San Diego for two days of education, networking and collaboration. Leading experts from across the industry shared some of the latest research in sessions and posters with over 600 attendees. The foremost companies in cannabis testing, research and extraction brought their teams to exhibit and share cutting edge technology solutions.

Ken Snoke, president of Emerald Scientific, delivers the opening remarks

The diversity in research topics was immense. Speakers touched on all of the latest research trends, including tissue culture as a micropropagation technique, phenotype hunting, pharmaceutical product formulation, chromatography methods and manufacturing standards, to name a few.

On the first day of the event, Ken Snoke, president of Emerald Scientific, gave his opening remarks, highlighting the importance of data-driven decisions in our industry, and how those decisions provide the framework and foundation for sound progress. “But data also fuels discovery,” says Snoke, discussing his remarks from the event. “I told a story of my own experience in San Diego almost 30 years ago while working in biotech, and how data analysis in a relatively mundane and routine screening program led to discovery. And how we (the folks at Emerald) believe that when we get our attendees together, that the networking and science/data that comes from this conference will not only support data-driven decisions for the foundation of the industry, but it will also lead to discovery. And that’s why we do this,” Snoke added.

Arun Apte, CEO of CloudLIMS, discusses his poster with an attendee

Snoke says the quality of the content at the poster session was phenomenal and engaging. “We had over 500 attendees so we continue to grow, but it’s not just about growth for us,” says Snoke. “It’s about the quality of the content, and providing a forum for networking around that content. I met a scientist that said this conference renewed his faith in our industry. So I firmly believe that the event has and will continue to have a profound and immensely positive impact on our industry.”

Introducing speakers as one of the chairs for first session focused on production, Dr. Markus Roggen says he found a number of speakers delivered fascinating talks. “This year’s lineup of presentations and posters really showcase how far the cannabis industry has come along,” says Dr. Roggen. “The presentations by Roger Little, PhD and Monica Vialpando, PhD, both showed how basic research and the transfer of knowledge from other industries can push cannabis science forward. Dr. Brian Rohrback’s presentation on the use of chemometrics in the production of pharmaceutical cannabis formulations was particular inspiring.”

Roger Little, Ph.D., owner of CTA, LLC, presents his research

Shortly after Snoke gave his opening remarks, Dr. Roggen introduced the first speaker, Roger Little, Ph.D., owner of CTA, LLC. He presented his research findings on phenotype hunting and breeding with the help of a cannabis-testing laboratory. He discussed his experience working with local breeders and growers in Northern California to identify high-potency plants early in their growth. “You can effectively screen juvenile plants to predict THC potency at harvest,” says Dr. Little. The other research he discussed included some interesting findings on the role of Methyl jasmonate as an immune-response trigger. “I was looking at terpenes in other plants and there is this chemical called methyl jasmonate,” says Dr. Little. “It is produced in large numbers of other plants and is an immune response stimulator. This is produced from anything trying to harm the plant such as a yeast infection or mites biting the stem.” Dr. Little says that the terpene has been used on strawberries to increase vitamin C content and on tobacco plants to increase nicotine content, among other uses. “It is a very potent and ubiquitous molecule,” says Dr. Little. “Cannabis plants’ immune-response is protecting the seeds with cannabinoid production. We can trick plants to think they are infected and thus produce more cannabinoids, stimulating them to produce their own jasmonate.”

Dr. Hope Jones, chief scientific officer of C4 Laboratories, spoke about tissue culture as an effective micropropagation technique, providing attendees with a basic understanding of the science behind it, and giving some estimates for how it could effectively replace cloning and the use of mother plants. You could overhear attendees discussing her talk throughout the remainder of the show.

Dr. Hope Jones, chief scientific officer at C4 Laboratories, discusses tissue culture during her talk

Dr. Jones has worked with CIJ on a series of articles to help explain cannabis tissue culture, which you can find here. “In this example, we started with one vessel with 4 explants,” says Dr. Jones. “Which when subcultured 4-6 weeks later, we now have 4 vessels with 16 plants.” She says this is instrumental in understanding how tissue culture micropropagation can help growers scale without the need for a ton of space and maintenance. From a single explant, you can potentially generate 70,000 plants after 48 weeks, according to Dr. Jones.

Those topics were just the first two of many presentations at Emerald Conference. You can take a look at some of the other presentation abstracts in the agenda here. The 5th Annual Emerald Conference in 2019 will be held February 28th through March 1st in San Diego next year.

Swetha Kaul, PhD

An Insider’s View: How Labs Conduct Cannabis Mold Testing

By Swetha Kaul, PhD
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Swetha Kaul, PhD

As both recreational and medical cannabis legalization continues to progress across the country, each state is tasked with developing regulatory requirements to ensure that customers and patients receive clean cannabis for consumption. This requires cannabis to undergo laboratory testing that analyzes the presence of microbial impurities including yeast and mold.

Some states, such as Colorado, Nevada, Maine, Illinois and Massachusetts use total yeast and mold count testing (TYMC) and set a maximum yeast and mold count threshold that cultivators must fall below. Other states, such as California, require the detection of species-specific strains of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus), which requires analyzing the DNA of a cannabis sample through polymerase chain reaction testing, also known as PCR.

Differences in state regulations can lead to different microbiological techniques implemented for testing.Before diving in further, it is important to understand the scientific approach. Laboratory testing requirements for cannabis can be separated into two categories: analytical chemistry methods and microbiological methods.

Analytical chemistry is the science of qualitatively and quantitatively determining the chemical components of a substance, and usually consists of some kind of separation followed by detection. Analytical methods are used to uncover the potency of cannabis, analyze the terpene profile and to detect the presence of pesticides, chemical residues, residuals solvents, heavy metals and mycotoxins. Analytical testing methods are performed first before proceeding to microbiological methods.

Petri dish containing the fungus Aspergillus flavus
Petri dish containing the fungus Aspergillus flavus. It produces carcinogenic aflatoxins, which can contaminate certain foods and cause aspergillosis, an invasive fungal disease.
Photo courtesy of USDA ARS & Peggy Greb.

Microbiological methods dive deeper into cannabis at a cellular level to uncover microbial impurities such as yeast, mold and bacteria. The techniques utilized in microbiological methods are very different from traditional analytical chemistry methods in both the way they are performed and target of the analysis. Differences in state regulations can lead to different microbiological techniques implemented for testing. There are a variety of cell and molecular biology techniques that can be used for detecting microbial impurities, but most can be separated into two categories:

  1. Methods to determine total microbial cell numbers, which typically utilizes cell culture, which involves growing cells in favorable conditions and plating, spreading the sample evenly in a container like a petri dish. The total yeast and mold count (TYMC) test follows this method.
  2. Molecular methods intended to detect specific species of mold, such as harmful aspergillus mold strains, which typically involves testing for the presence of unique DNA sequences such as Polymerase Chain Reaction (PCR).

Among states that have legalized some form of cannabis use and put forth regulations, there appears to be a broad consensus that the laboratories should test for potency (cannabinoids concentration), pesticides (or chemical residues) and residual solvents at a minimum. On the other hand, microbial testing requirements, particularly for mold, appear to vary greatly from state to state. Oregon requires random testing for mold and mildew without any details on test type. In Colorado, Nevada, Maine, Illinois and Massachusetts, regulations explicitly state the use of TYMC for the detection of mold. In California, the recently released emergency regulations require testing for specific species of
Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus), which are difficult to differentiate on a plate and would require a DNA-based approach. Since there are differences in costs associated and data produced by these methods, this issue will impact product costs for cultivators, which will affect cannabis prices for consumers.


dSPE cleanups

The Grass Isn’t Always Greener: Removal of Purple Pigmentation from Cannabis

By Danielle Mackowsky
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dSPE cleanups
Cannabis strains used (clockwise from top left): Agent Orange, Tahoe OG, Blue Skunk, Grand Daddy and Grape Drink

Cannabis-testing laboratories have the challenge of removing a variety of unwanted matrix components from plant material prior to running extracts on their LC-MS/MS or GC-MS. The complexity of the cannabis plant presents additional analytical challenges that do not need to be accounted for in other agricultural products. Up to a third of the overall mass of cannabis seed, half of usable flower and nearly all extracts can be contributed to essential oils such as terpenes, flavonoids and actual cannabinoid content1. The biodiversity of this plant is exhibited in the over 2,000 unique strains that have been identified, each with their own pigmentation, cannabinoid profile and overall suggested medicinal use2. While novel methods have been developed for the removal of chlorophyll, few, if any, sample preparation methods have been devoted to removal of other colored pigments from cannabis.

Cannabis samples following QuEChERS extraction

Sample Preparation

Cannabis samples from four strains of plant (Purple Drink, Tahoe OG, Grand Daddy and Agent Orange) were hydrated using deionized water. Following the addition of 10 mL acetonitrile, samples were homogenized using a SPEX Geno/Grinder and stainless steel grinding balls. QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) non-buffered extraction salts were then added and samples were shaken. Following centrifugation, an aliquot of the supernatant was transferred to various blends of dispersive SPE (dSPE) salts packed into centrifugation tubes. All dSPE tubes were vortexed prior to being centrifuged. Resulting supernatant was transferred to clear auto sampler vials for visual analysis. Recoveries of 48 pesticides and four mycotoxins were determined for the two dSPE blends that provided the most pigmentation removal.

Seven dSPE blends were evaluated for their ability to remove both chlorophyll and purple pigmentation from cannabis plant material:

  • 150 mg MgSO4, 50 mg PSA, 50 mg C18, 50 mg Chlorofiltr®
  • 150 mg MgSO4, 50 mg C18, 50 mg Chlorofiltr®
  • 150 mg MgSO4, 50 mg PSA
  • 150 mg MgSO4, 25 mg C18
  • 150 mg MgSO4, 50 mg PSA, 50 mg C18
  • 150 mg MgSO4, 25 mg PSA, 7.5 mg GCB
  • 150 mg MgSO4, 50 mg PSA, 50 mg C18, 50 mg GCB

Based on the coloration of the resulting extracts, blends A, F and G were determined to be the most effective in removing both chlorophyll (all cannabis strains) and purple pigments (Purple Drink and Grand Daddy). Previous research regarding the ability of large quantities of GCB to retain planar pesticides allowed for the exclusion of blend G from further analyte quantitation3. The recoveries of the 48 selected pesticides and four mycotoxins for blends A and F were determined.

dSPE cleanups
Grand Daddy following various dSPE cleanups


A blend of MgSO4, C18, PSA and Chlorofiltr® allowed for the most sample clean up, without loss of pesticides and mycotoxins, for all cannabis samples tested. Average recovery of the 47 pesticides and five mycotoxins using the selected dSPE blend was 75.6% were as the average recovery when including GCB instead of Chlorofiltr® was 67.6%. Regardless of the sample’s original pigmentation, this blend successfully removed both chlorophyll and purple hues from all strains tested. The other six dSPE blends evaluated were unable to provide the sample clean up needed or had previously demonstrated to be detrimental to the recovery of pesticides routinely analyzed in cannabis.


(1)           Recommended methods for the identification and analysis of cannabis and cannabis products, United Nations Office of Drugs and Crime (2009)

(2)            W. Ross, Newsweek, (2016)

(3)            Koesukwiwat, Urairat, et al. “High Throughput Analysis of 150 Pesticides in Fruits and Vegetables Using QuEChERS and Low-Pressure Gas Chromatography Time-of-Flight Mass Spectrometry.” Journal of Chromatography A, vol. 1217, no. 43, 2010, pp. 6692–6703., doi:10.1016/j.chroma.2010.05.012.

Microbiology 101 Part Two

By Kathy Knutson, Ph.D.
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Microbiology 101 Part One introduced the reader to the science of microbiology and sources of microbes. In Part Two, we discuss the control of microorganisms in your products.

Part 2

The cannabis industry is probably more informed about patients and consumers of their products than the general food industry. In addition to routine illness and stress in the population, cannabis consumers are fighting cancer, HIV/AIDS and other immune disorders. Consumers who are already ill are immunocompromised. Transplant recipients purposely have their immune system suppressed in the process of a successful transplant. These consumers have pre-existing conditions where the immune system is weakened. If the immunocompromised consumer is exposed to viral or bacterial pathogens through cannabis products, the consumer is more likely to suffer from a viral infection or foodborne illness as a secondary illness to the primary illness. In the case of consumers with weakened immune systems, it could literally kill them.Bacteria, yeast, and mold are present in all environments.

The cannabis industry shoulders great responsibility in both the medical and adult use markets. In addition to avoiding chemical hazards and determining the potency of the product, the cannabis industry must manufacture products safe for consumption. There are three ways to control pathogens and ensure a safe product: prevent them from entering, kill them and control their growth.

Prevent microorganisms from getting in

Think about everything that is outdoors that will physically come in a door to your facility. Control the quality of ingredients, packaging, equipment lubricants, cleaning agents and sanitizers. Monitor employee hygiene. Next, you control everything within your walls: employees, materials, supplies, equipment and the environment. You control receiving, employee entrance, storage, manufacturing, packaging and distribution. At every step in the process, your job is to prevent the transfer of pathogens into the product from these sources.

Kill microorganisms

Colorized low-temperature electron micrograph of a cluster of E. coli bacteria.
Image courtesy of USDA ARS & Eric Erbe

The combination of raw materials to manufacture your product is likely to include naturally occurring pathogens. Traditional heat methods like roasting and baking will kill most pathogens. Remember, sterility is not the goal. The concern is that a manufacturer uses heat to achieve organoleptic qualities like color and texture, but the combination of time and temperature may not achieve safety. It is only with a validated process that safety is confirmed. If we model safety after what is required of food manufacturers by the Food and Drug Administration, validation of processes that control pathogens is required. In addition to traditional heat methods, non-thermal methods for control of pathogens includes irradiation and high pressure processing and are appropriate for highly priced goods, e.g. juice. Killing is achieved in the manufacturing environment and on processing equipment surfaces after cleaning and by sanitizing.

If you have done everything reasonable to stop microorganisms from getting in the product and you have a validated step to kill pathogens, you may still have spoilage microorganisms in the product. It is important that all pathogens have been eliminated. Examples of pathogens include Salmonella, pathogenic Escherichia coli, also called Shiga toxin-producing E. coli (STEC) and Listeria monocytogenes. These three common pathogens are easily destroyed by proper heat methods. Despite steps taken to kill pathogens, it is theoretically possible a pathogen is reintroduced after the kill step and before packaging is sealed at very low numbers in the product. Doctors do not know how many cells are required for a consumer to get ill, and the immunocompromised consumer is more susceptible to illness. Lab methods for the three pathogens mentioned are designed to detect very low cell numbers. Packaging and control of growth factors will stop pathogens from growing in the product, if present.

Control the growth of microorganisms

These growth factors will control the growth of pathogens, and you can use the factors to control spoilage microbes as well. To grow, microbes need the same things we do: a comfortable temperature, water, nutrients (food), oxygen, and a comfortable level of acid. In the lab, we want to find the pathogen, so we optimize these factors for growth. When you control growth in your product, one hurdle may be enough to stop growth; sometimes multiple hurdles are needed in combination. Bacteria, yeast, and mold are present in all environments. They are at the bottom of the ocean under pressure. They are in hot springs at the temperature of boiling water. The diversity is immense. Luckily, we can focus on the growth factors for human pathogens, like Salmonella, pathogenic E. coli, and Listeria monocytogenes.

The petri dishes show sterilization effects of negative air ionization on a chamber aerosolized with Salmonella enteritidis. The left sample is untreated; the right, treated. Photo courtesy of USDA ARS & Ken Hammond

Temperature. Human pathogens prefer to grow at the temperature of the human body. In manufacture, keep the time a product is in the range of 40oF to 140oF as short as possible. You control pathogens when your product is at very hot or very cold temperatures. Once the product cools after a kill step in manufacturing, it is critical to not reintroduce a pathogen from the environment or personnel. Clean equipment and packaging play key roles in preventing re-contamination of the product.

Water. At high temperatures as in baking or roasting, there is killing, but there is also the removal of water. In the drying process that is not at high temperature, water is removed to stop the growth of mold. This one hurdle is all that is needed. Even before mold is controlled, bacterial and yeast growth will stop. Many cannabis candies are safe, because water is not available for pathogen growth. Packaging is key to keep moisture out of the product.

Nutrients. In general, nutrients are going to be available for pathogen growth and cannot be controlled. In most products nutrients cannot be removed, however, recipes can be adjusted. Recipes for processed food add preservatives to control growth. In cannabis as in many plants, there may be natural compounds which act as preservatives.

Oxygen. With the great diversity of bacteria, there are bacteria that require the same oxygen we breathe, and mold only grows in oxygen. There are bacteria that only grow in the absence of oxygen, e.g. the bacteria responsible for botulism. And then there are the bacteria and yeast in between, growing with or without oxygen. Unfortunately, most human pathogens will grow with or without oxygen, but slowly without oxygen. The latter describes the growth of Salmonella, E. coli, and Listeria. While a package seals out air, the growth is very slow. Once a package is opened and the product is exposed to air, growth accelerates.

Acid. Fermented or acidified products have a higher level of acid than non-acid products; the acid acts as a natural preservative. The more acid, the more growth is inhibited. Generally, acid is a hurdle to growth, however and because of diversity, some bacteria prefer acid, like probiotics which are non-pathogenic. Some pathogens, like E. coli, have been found to grow in low acid foods, e.g. juice, even though the preference is for non-acidic environments.

Each facility is unique to its materials, people, equipment and product. A safe product is made by following Good Agricultural Practices for the cannabis, by following Good Manufacturing Practices and by suppressing pathogens by preventing them coming in, killing them and controlling their growth factors. Future articles will cover Hazard Analysis and Critical Control Points (HACCP) and food safety in more detail.


Proficiency Testing in the Cannabis Industry: An Inside Look

By Cannabis Industry Journal Staff
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Cannabis Labs Virtual Conference: Part 4

Proficiency Testing in the Cannabis Industry: An Inside Look
By Amanda Rigdon, Chief Technical Officer, Emerald Scientific

This presentation covers specifics of different proficiency testing schemes available to the cannabis industry. Additionally, specific challenges facing both laboratories and PT providers in the cannabis industry will be addressed. Data relating to residual solvent and potency proficiency testing will be presented.

Ask The Expert: Exploring Cannabis Laboratory Accreditation Part 4

By Aaron G. Biros
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In the first part of this series, we spoke with Michelle Bradac, senior accreditation officer at A2LA, to learn the basics of cannabis laboratory accreditation. In the second part, we sat down with Roger Brauninger, A2LA Biosafety Program manager, to learn why states are looking to lab accreditation in their regulations for the cannabis industry. In the third part, we heard from Michael DeGregorio, chief executive officer of Konocti Analytics, Inc., discussing method development in the cannabis testing industry and his experience with getting accredited.

In the fourth and final part of this series, we sit down with Susan Audino, Ph.D., an A2LA lead assessor and instructor, laboratory consultant and board member for the Center for Research on Environmental Medicine in Maryland. Dr. Audino will share some insights into method validation and the most technical aspects of laboratory accreditation.

Susan Audino, Ph.D.

Susan Audino obtained her Ph.D. in Chemistry with an analytical chemistry major, physical and biochemistry minor areas. She currently owns and operates a consulting firm to service chemical and biological laboratories. Susan has been studying the chemistry and applications of cannabinoids and provides scientific and technical guidance to cannabis dispensaries, testing laboratories and medical personnel. Dr. Audino’s interest most directly involves cannabis consumer safety and protection, and promotes active research towards the development of official test methods specifically for the cannabis industry, and to advocate appropriate clinical research. In addition to serving on Expert Review Panels, she is also chairing the first Cannabis Advisory Panel and working group with AOAC International, is a member of the Executive Committee of the ASTM Cannabis Section and has consulted to numerous cannabis laboratories and state regulatory bodies.

CannabisIndustryJournal: What are the some of the most significant technical issues facing an accreditation body when assessing a cannabis-testing laboratory?

Susan: From the AB perspective, there needs to be a high level of expertise to evaluate the merits and scientific soundness of laboratory-developed analytical test methods. Because there are presently no standard or consensus test methods available, laboratories are required to develop their own methods, which need to be valid. Validating methods require a rigorous series of tests and statistical analyses to ensure the correctness and reliability of the laboratory’s product, which is– the test report.

CIJ: When is method validation required and how does this differ from system suitability?

Susan: Method validation is required whenever the laboratory modifies a currently accepted consensus or standard test method, or when the laboratory develops its own method. Method validation is characterized by a series of analytical performance criteria including determinations of accuracy, precision, linearity, specification, limit of detection, and limit of quantitation. The determination of system suitability requires a series of deliberate variations of parameters to ensure the complete system, that is all instrument(s) as well as the analytical method, is maintained throughout the entire analytical process. Traditionally, method validation has been referred to as “ruggedness” and system suitability as “robustness.”

CIJ: What are the most important aspects of method validation that must be taken into account? 

Susan: In keeping with the FDA guidelines and other accepted criteria, I tend to recommend the International Conference on Harmonization (ICH), particularly Q 2A, which is a widely recognized program that discusses the pertinent characteristics of method validation. This include: method specification, linearity, range, accuracy, and precision (e.g., repeatability, intermediate precision, reproducibility). As mentioned earlier, system suitability is also a critical element and although related to method validation, does require its own protocol.

CIJ: What three areas do you see the laboratory having the hardest time with in preparing for accreditation? 

Susan: My responses to this question assume the laboratory employs appropriate instruments to perform the necessary analyses, and that the laboratory employs personnel with experience and knowledge appropriate to develop test methods and interpret test results.

  • By and large, method validation that is not appropriate to the scope of their intended work. Driving this is an overall lack of information about method validation. Oftentimes there is an assumption that multiple recoveries of CRMs constitute “validation”. While it may be one element, this only demonstrates the instrument’s suitability. My recommendation is to utilize any one of a number of good single laboratory validation protocols. Options include, but are not limited to AOAC International, American Chemical Society, ASTM, and ICH protocols.
  • Second is the lack of statistically sound sampling protocols for those laboratories that are mandated by their governing states to go to the field to sample the product from required batches. Sampling protocols needs to address the heterogeneity of the plant, defining the batch, and determining/collecting a sample of sufficient quantity that will be both large enough and representative of the population, and to provide the laboratory an adequate amount from which to sub-sample.
  • Third, sample preparation. This is somewhat intertwined with my previous point. Once an appropriate sample has been collected, preparation must be relevant to the appropriate technology and assay. It is unlikely that a laboratory can perform a single preparation that is amenable to comprehensive testing.

Steep Hill Expands To Oregon

By Aaron G. Biros
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Last week, Steep Hill announced they are expanding into Oregon with a laboratory in Portland. According to the press release, the company has licensed its testing technology to Dr. Carl Balog, a renowned pain and addiction physician.

Steep Hill has expanded significantly over the past year, including new laboratories in Pennsylvania, Maryland, Washington D.C. and Hawaii, among other states. The Berkeley-based company works in lab testing, research and development, licensing, genetics and remote testing. In 2008, Steep Hill opened the first-ever commercial cannabis-testing laboratory in the country.

Jmîchaeĺe Keller, president and chief executive officer of Steep Hill, says this is a development that will help them better understand cannabis chemistry and its medical applications. “We are pleased to announce our expansion into Oregon and especially pleased to partner with Dr. Balog, a physician who brings years of pain and addiction experience to the Steep Hill body of expertise,” says Keller. “In addition, Dr. Balog plans to use his specialized knowledge to aid Steep Hill’s research and development efforts to broaden our understanding of cannabis chemistry and to explore its wider medical applications. In partnering with Dr. Balog, we hope that Steep Hill will be able to help physicians around the United States to curb the opioid epidemic by offering Steep Hill Verified™ medicinal cannabis as an alternative to a crisis that plagues this country.”

Examination of cannabis prior to testing- credit Steep Hill Labs, Inc.

Dr. Balog, now owner and medical director of Steep Hill Oregon, says medical cannabis could be an excellent harm reduction tool, and hints at it being a possible tool in the opioid crisis. “I deal with the consequences of the opioid epidemic on a daily basis as a pain and addiction specialist,” says Dr. Balog. “The growing trend of using cannabis products as an alternative to opioids highlights the need for regulated testing. Because of the variability of marijuana preparations, testing ensures that scientific rigor is applied in a standardized way. I am dedicated to ensuring that patients have access to safe, tested cannabis, free from contaminants and to verified labels that can be trusted for their content.”

They expect Steep Hill Oregon to be open for business in the second quarter of 2018.

Using Cloud-Based LIMS To Improve Efficiency In Cannabis Labs

By Shonali Paul
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Cannabis testing laboratories around the country are expanding quickly, taking on new clients and growing their business incrementally. Many of these labs are receiving a large number of test requests from growers for potency testing, terpene profiling, pesticide screening, residual solvent screening, heavy metal testing, microbial analysis and even genetic testing. To keep pace with the number of test requests received, efficient data, sample and test management is imperative.

Considering the magnitude of cannabis testing, data management using spreadsheets is a serious impediment to quality assurance. Data being recorded in spreadsheets is error-prone and difficult to manage. Furthermore, using spreadsheets does not allow labs to adhere to regulatory guidelines that demand strict accounting for every gram of the sample, right from reception, consumption for testing, to disposal.

Log samples, keep track of Chain of Custody(CoC), track samples from initial location in the lab through disposal by recording location, custodians and other metadata

To overcome such data management challenges and improve the operational efficiency of cannabis testing laboratories, a Laboratory Information Management System (LIMS) plays a significant role. LIMS are much more capable than spreadsheets and paper-based tools for managing analytical and operational activities. LIMS enhances the productivity and quality by eliminating the manual data entry. With its built-in audit trail capability, LIMS helps labs adhere to regulatory standards.

LIMS can provide companies with a method to manage samples, records and test results, and ensures regulatory compliance by increasing traceability. LIMS can also be integrated with other lab instrumentation and enterprise systems, enabling easier transmission of information across the lab and the organization, reducing manual efforts and improving decision-making.

Account for the entire quantity of sample received, used and disposed

Multiple resources are also available to assist labs in preparing for quality assurance and accreditation, LIMS being one of them. LIMS can help cannabis labs with instrument integration, and automate reporting to help improve efficiencies and reduce errors. LIMS, such as CloudLIMS Lite, a cloud-based LIMS, automates cannabis-testing workflows right from sample collection, data recording, managing test chain of custody, sample weight accounting to report generation. With data security and audit trails, a LIMS provides traceable documentary evidence required to achieve ISO 17025 accreditation for highly regulated labs. Above all, cloud-enabled systems are often low in the total cost of acquisition, have maintenance outsourced, and are scalable to help meet the ever-changing business and regulatory compliance needs.

Incorporate all tests, instruments, sample information and result data (etc.) in one place

Cloud-based products are secure, easy to deploy and scalable. A cloud product is typically hosted on a server with a guaranteed uptime of 99.5%, allowing for a reliable system, accessible 24×7. Cloud-based LIMS have automatic data backup mechanism that allow for quick turnarounds in case of a server failure or in the eventuality of a natural disaster.

With LIMS in place, cannabis labs can manage sample and requisition-centric records, track sample quantity and location, integrate the test data, and provide online reports to clients. This in turn, reduces the turnaround time for testing and improves the operational efficiency. Besides, audit trail of each and every activity performed by the lab personnel is recorded in the system to ensure that the lab follows regulatory compliance.

Editor’s Note: This is a condensed version of a poster that was submitted and displayed at this year’s Cannabis Science Conference in Portland, Oregon. The authors of the original poster are Arun Apte, Stephen Goldman, Aditi Gade and Shonali Paul.