Fresh Focus: Microbiological Testing

Last month, I discussed product testing and some of its issues. This month, I want to cover more ideas regarding microbiological testing, but from the standpoint of sampling, choosing a lab, the kinds of tests to ask for and what to do with the results.

Sampling

Sampling could be a critical aspect of microbiological testing, and one shouldn’t cut corners when it comes to taking a sample. If you are contemplating testing, consider who will take the sample. Is your lab close enough to someone who can take the sample and not charge too much for that service? If not, then someone on staff needs to be trained about proper techniques to use in taking an uncontaminated sample.

Ask lab representatives to meet with you to discuss sampling on location. Not only can they help in designing a viable sampling plan, they can learn about the environment the sample will come from. They also can instruct you or your chosen sampler on how to take an aseptic sample.

Quality Control

Two labs may do the same kind of work, but the quality of work between labs may vary. A good analytical lab should have a quality control system in place that is organized in a manual you can look over during an on-site visit.

Good Laboratory Practices (GLP) have been developed for some analyses such as animal, drug and environmental testing. There also should be a Chain of Custody (COC) process that records the conditions of the sample upon receipt, who handled the sample and where and how long the sample was stored before tests were conducted.

Specific Analyses

Form a plan describing what and why you are sampling, what kind of tests you want performed and what actions you will take in response to the results.

Once you identify the pathogens you want to test for, get acquainted with the various methodologies for that organism. If time is of the essence, then rapid methods could be employed. Ask the laboratory leader to keep you informed about new research and development for new methodologies. Using new methods before approval by an outside organization involves some level of risk, so be educated.

Seek a clear understanding about the test methods so you will understand their sensitivity or selectivity for specific organisms. Some basic questions that will help you set up your testing program include:

-Where will the sample be run – a mobile lab or a commercial lab?
-Who will be taking the samples – your staff or the lab’s staff?
-How many samples will be run at one time?
-How often will they be run?
-How fast do you need the results?
-How will the results be validated?
-What are the costs?

By knowing your needs and understanding the capabilities of your lab, you should find a good match for your microbiological testing program. Having a plan with sound steps for handling the results should a positive come up will prepare you to make good decisions. But planning and monitoring are essential to managing an effective microbiological testing program.