False Positive in Micro Assessment

Hello everyone!

I have less than a year of experience in a food microbiology lab and am seeking advice from experts in the field. I’ve been tasked with addressing a non-conformance issue related to false positives for pathogens in samples, which seems to root from inadequate/poor lab techniques. This issue also involves retesting or sampling procedures. Could anyone provide guidance or share a relevant guideline that I could use as a basis for handling this situation?

;) 

is your lab fully accredited / certified? 

ask for the latest accreditation / certification and final non-conformances 

ask for laboratory methods (this should be listed on accreditation) if not ask for sampling laboratory procedures and staff training 

a full investigation shall be conducted by lab 

Can you tell us which pathogen tested false positive? 

Did the lab notify you that it was false positive? 

How do you know it was a false positive?