Technical Question
Below are some of the questions related to some technical things regarding Cherney and the testing we perform.
How much of my product is 125g?

Below are some handy conversion charts for you to utilize.

Grams Ounces Pounds
11 0.39 0.02
25 0.88 0.06
125 4.40 0.27
375 13.23 0.83
454 16.00 1.00
1500 52.91 3.31


Is Cherney Microbiological an accredited facility?

Absolutely we are! Below are our certifications as well as the link to them.

2986.01: Biological Field of Testing
2986.04: Chemical Field of Testing
2986.02: ISO/IEC 17043:2010 Proficiency Testing Providers

A2LA Accreditation Link:

What is the difference between VIDAS and Bio-Rad IQ Check?

These questions can get pretty deep when it comes to the science of it. Let me provide some basic differences without getting too far in-depth.

VIDAS is based on Enzyme-Linked Fluorescent Assay (ELFA) technology. The method looks for specific proteins in a sample using antibodies, antigens, and a fluorescent tag. VIDAS generates an RLU (Reflective Light Unit) and (based on the results) if it's past a certain value, it is considered presumptive-positive.

Bio-Rad IQ Check is based on Polymerase Chain Reaction (PCR) technology. This method looks for the specific DNA of an organism in your sample. Bio-Rad breaks apart the cell, revealing the DNA of the organism if it is present. It then attempts to replicate the DNA in cycles and graphs it to a curve. If the curve passes a certain threshold before it hits 40 cycles, the product is considered presumptive-positive.

There are pros and cons to both methods, but my best recommendation would be to speak with our technical team if you are looking to utilize either platform. Our Cherney College courses provide a lot of great information regarding methods and technology. For VIDAS and PCR, our Advanced Food Micro course would provide a lot of details.

What does the asterisk (*) mean on my CoA?

On your Certificate of Analysis (CoA) you may see an asterisk (*) on some of your results/counts. That is what we call an "estimated" sign.

All plate count methods have a range in which the colony count is statistically the most accurate. As an example - a yeast count is 10-150 CFU (or colony-forming units). If the colony count is in this range, there is no estimate. If it is outside that range the estimate is applied because there is increased statistical error in the result. It is a practice that is stated in reference methods for colony counting rules.

This does not mean that your results are incorrect. Reference methods and studies show that statistically there is a margin of error outside of that countable range.

What does cfu stand for?

CFU stands for Colony Forming Units. It has a long and dredged out definition but essentially it is a basic unit for plate counts. Each CFU is a viable colony that grew on the plate.

These colonies had the potential to grow in your product. We just gave them the perfect conditions to grow rapidly to ensure you know what the potential hazard is.

Pathogens In the Environment?

Both Listeria and Salmonella have the potential to be extremely detrimental in your production environment. Each pathogen has its own specific growth niches and can exist in places you may not even expect. Listeria has growth potential in cool and wet environments whereas Salmonella can survive in warm and dry environments. Without proper sanitation and hygiene, these pathogens can cross-contaminate both the processing equipment and, eventually, the final product. The best thing to do is be proactive and try to seek out niches where Listeria/Salmonella may be growing and do some pathogen testing!

Currently we have two platforms for pathogen testing, VIDAS (ELFA- Enzyme Linked Fluorescent Assay) and iQ Check (PCR- Polymerase Chain Reaction).

Not able to find an answer to your questions? Contact us by phone (920-406-8300) or by email (button below) to work with our Client Services Team. We will get the answer for you!
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