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

Version

Version 1.0

Status

Status Published

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.