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Microbial Contamination


Cannabis Leaf
Cannabis Leaf

Quantitative Polymerase Chain Reaction

Let's break down these processes step by step, focusing on their importance in cannabis testing for microbial contaminants.

TSB as a Growth Media in Whirl Pack Bags

TSB, or Tryptic Soy Broth, is a nutrient-rich growth media commonly used in microbiology to cultivate a wide range of bacteria. When used in whirl pack bags, TSB provides an ideal environment for multiplying any bacteria present in a cannabis sample. Here's how it works: a sample of cannabis is placed in a whirl pack bag containing TSB and then incubated for a specified period. During incubation, the nutrients in TSB support bacterial growth, making any contamination more detectable. This method is particularly useful for enriching bacterial populations to detectable levels before conducting further analysis, such as DNA isolation.

DNA Isolation in Cannabis for Medicinal Genomics

DNA isolation from cannabis involves extracting the genetic material of any microbes present on the plant. This process begins with breaking open the microbial cells (lysis) to release their DNA. This can involve physical methods like grinding, chemical methods using detergents to dissolve cell membranes, or enzymes to digest cellular components. The DNA is then separated from the rest of the cell debris through a series of purification steps. Medicinal Genomics utilizes specialized protocols and kits designed for cannabis samples, ensuring that the DNA isolated is of high quality and free from plant contaminants, ready for qPCR analysis.

Medicinal Genomics qPCR Assays for Detecting Microbial Contaminants

Quantitative Polymerase Chain Reaction (qPCR) assays by Medicinal Genomics leverage the isolated DNA to detect and quantify microbial contaminants. qPCR is a highly sensitive technique that amplifies specific DNA sequences of interest - in this case, sequences unique to microbial contaminants like bacteria and fungi. By using primers that are specific to the DNA of target microbes, the qPCR assay can rapidly amplify these sequences if they are present, making even small amounts of microbial DNA detectable. Each cycle of the qPCR process doubles the amount of targeted DNA, and the accumulation of DNA is monitored in real-time, allowing for the quantification of microbial load in the sample.

Agilent Aria Mx Detection Using Fluorescent Probes

The Agilent Aria Mx utilizes fluorescent probes to detect the analyte of interest during qPCR assays. These probes are designed to attach to specific DNA sequences during the amplification process. Each probe contains a fluorescent dye, which only emits light when the probe is bound to its target DNA sequence and the DNA polymerase enzyme cleaves the probe during amplification. The Aria Mx instrument detects the intensity of the fluorescence emitted, which increases with each cycle of amplification, correlating directly with the amount of target DNA present.


By analyzing the fluorescence data, the Aria Mx can precisely quantify the level of microbial contaminants in a cannabis sample, offering a powerful tool for ensuring product safety and compliance with regulatory standards.

Together, these technologies and methods form a comprehensive approach to detecting and quantifying microbial contaminants in cannabis, ensuring product safety for medicinal and recreational use.


Plating is a microbiological technique where a small volume of a liquid sample is spread across the surface of a nutrient-rich agar plate. As the sample incubates, the nutrients in the agar support the growth of any bacteria or fungi present, allowing them to form visible colonies.


Each colony represents an individual microorganism or a cluster of the same microorganisms that were in the original sample. By counting these colonies, scientists can estimate the number of microbes in the sample, identifying and quantifying microbial contamination in cannabis products. This method is straightforward and effective for assessing the microbial safety of cannabis.

Cannabis Leaf
Cannabis Leaf
qPCR amplification plot

How does Cannabis ChemLab Stand Out?

Cannabis ChemLab excels in its unique capability to speciate Aspergillus, offering unparalleled precision in identifying and distinguishing between the specific strains of this mold: Fumigati, Flavi, Nigri, and Terrei. Utilizing advanced molecular techniques, our lab not only detects the presence of Aspergillus but also pinpoints the exact species, ensuring a level of safety and specificity unmatched in the industry. This targeted approach empowers our clients with detailed insights into potential mycotoxin risks, elevating product safety and compliance standards to protect consumer health.


The Aria Mx system identifies microbial contaminants in cannabis by employing qPCR technology, which amplifies specific microbial DNA. As the DNA replicates, fluorescent probes attached to the target sequences emit light, which the Aria Mx measures. This process allows for precise quantification of microbial levels, offering a highly accurate assessment of contamination to ensure product safety and quality.

Agilent AriaMx

Medicinal Genomics

Medicinal Genomics is a pioneering company specializing in genetic solutions and testing technologies for the cannabis industry. It provides advanced tools for the identification and quantification of microbial contaminants in cannabis products.


Cannabis ChemLab leverages Medicinal Genomics' cutting-edge qPCR assays to accurately test for specific analytes, including various microbial contaminants like total yeast and mold, total aerobic bacteria, bile-tolerant gram-negative bacteria, Salmonella, STEC E. coli, and Aspergillus species. By utilizing these sophisticated genetic testing methods,


Cannabis ChemLab ensures high standards of safety and quality in cannabis products, adhering to regulatory requirements and protecting consumer health.


3M Petrifilm offers a streamlined solution for microbial testing, combining nutrients, a gelling agent, and indicators on a ready-to-use film. After inoculating the film with a sample and incubating, users can directly count the resulting bacterial colonies. This efficient approach simplifies traditional testing methods, providing rapid and accurate results with minimal preparation.

3M Petrifilm

3M Petrifilm 

3M Petrifilm represents a significant advancement in microbiological testing, offering an efficient, reliable alternative to conventional agar plates for detecting and quantifying microbial contaminants. Each Petrifilm is a compact, ready-to-use testing platform that integrates a solid culture medium, indicators, and a gelling agent.


This innovative design allows for the direct inoculation of the film with a sample, which is then incubated to promote the growth of microorganisms. Distinctive color changes and the formation of colonies enable easy enumeration and differentiation of the microbes present.

Cannabis ChemLab utilizes 3M Petrifilm to streamline its microbial testing processes, specifically targeting Total Yeast and Mold, Total Aerobic Bacteria, Bile Tolerant Gram Negative Bacteria, and Total Coliform. For each of these analytes, a specific type of Petrifilm is selected based on its tailored culture medium and indicators that are optimized for the growth and identification of the target microorganism group.


After inoculating the Petrifilm with a cannabis sample, it is incubated under conditions conducive to the growth of the target microbes. Yeast and molds, for instance, form colored colonies that are distinguishable under specific lighting, while aerobic bacteria and coliforms produce colonies that can be easily counted due to unique color-changing indicators. Bile Tolerant Gram Negative Bacteria are identified through their ability to grow in a bile-containing medium, indicating potential fecal contamination.

By employing 3M Petrifilm, Cannabis ChemLab benefits from a simplified workflow, reduced incubation times, and minimized use of bulky materials like agar plates and glassware. This method enhances the lab's capability to provide rapid, accurate microbial testing services for cannabis products, ensuring compliance with safety standards and protecting consumer health.


The use of Petrifilm for these total count tests allows Cannabis ChemLab to efficiently monitor and control the microbial quality of cannabis, ensuring products meet regulatory requirements and are safe for consumption.

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