Ask an Expert with David Roth - Estimated Levels
Overview
Eurofins Microbiology Laboratories, Inc. is made up of a network of microbiology labs located all throughout the US to support microbiological testing needs. Each lab has dedicated customer support so you get answers fast. Our Ask an Expert Series showcases our scientists from around the country and answers questions customers frequently ask. Videos are published weekly on all of social media platforms.
Ask an Expert Series - Topic #12
When I see "est." against a reported microbial count, what does it mean?
"Methods that are based on counting colonies on agar an plate will have set low and high limits for the number of colonies on a plate in order to report with the greatest accuracy. This is known as the countable range. For each sample, a series of dilutions are plated to increase the chance that at least one dilution falls into this range. However, there are times when we can only count the colonies from one dilution, and the number is above or below the countable range. In these cases, we calculate the result from the count and dilution as normal, and label it with “est.” to show that the result is an estimate from an “out of range” count. Reach out to your nearest Eurofins Microbiology Lab to learn more!" - David Roth, Senior Analytical Services Manager of Eurofins Microbiology Laboratories, Inc. in Madison, WI
