If there is no growth in a microbiology test during the specified incubation interval, can the sample be incubated until growth occurs?

Document ID

Document ID TE1331

Published Date

Published Date 12/03/2017
Question
If there is no growth in a microbiology test during the specified incubation interval, can the sample be incubated until growth occurs?
Summary
No growth in a microbiology test
Answer
Do not keep incubating a sample until growth occurs. If a method indicates an incubation period of 24-48 hours, waiting longer than that period until growth occurs is likely the result of contamination and should not be counted.