Microbiologist I
Posted May 5, 2026 · We last checked this listing on Oct 6, 2026
Likely interview questions for this role
Written from this job description, not a generic list. Each one notes what the interviewer is really checking.
About your past
Tell me about a time you caught a mistake in your own lab work. How did you find it, and what did you do next?
What they are checking: Whether they own errors openly, which matters more than never making one in a food safety lab.
Describe a time you followed a procedure you thought could be improved. What did you do about it?
What they are checking: Whether they follow the written method while raising changes through the proper channel instead of improvising.
What would you do
Your positive control fails on a test run near the end of your shift. What do you do?
What they are checking: Whether they stop and investigate instead of reporting results that cannot be trusted just to finish on time.
A result comes back out of specification for a dietary supplement lot. Who do you tell, and what do you hold off on doing?
What they are checking: Whether they follow the escalation path and avoid retesting until they get a passing number.
You have a stack of routine samples and someone from production asks you to rush one ahead of the rest. How do you handle that?
What they are checking: Whether they can balance plant needs against turnaround fairness and keep a lead informed about priority changes.
About the work
Walk me through how you would run a routine plate count on a probiotic culture sample, from receiving the sample to reporting the result.
What they are checking: Whether they know the full chain of aseptic technique, dilution, incubation and reading, not just one isolated step.
You log every result in the SAP Quality Management module. What does good documentation look like to you, and what would you never do on a lab record?
What they are checking: Whether they understand that a record must be complete, contemporaneous and never backfilled or overwritten without a trail.
This lab works under ISO 22000, NSF and GLP. Tell me what any one of those meant for how you actually worked day to day.
What they are checking: Whether quality systems are something they have lived inside, or only a phrase they have read on a résumé.
How do you check that a balance, pipette or incubator is in calibration before you trust it for a test?
What they are checking: Whether they treat equipment checks as part of the test itself rather than someone else's job.
How do you keep from cross-contaminating cultures when you are handling several strains in the same day?
What they are checking: Whether they have practical habits for segregation and aseptic work with live cultures and probiotics.
What GMP habits matter most when you are handling and storing food and supplement samples in the lab?
What they are checking: Whether they connect sample storage, labeling and chain of custody to the reliability of the final result.
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Practice this out loudThe full job description
As published by IFF.