These practices provide a uniform set of counting, calculating, and reporting procedures for ASTM test methods in microbiology.

The counting rules provide a best attainable estimate of microorganisms in the sample, since the samples cannot be held and reanalyzed at a later date.

1. Scope

1.1 These practices cover recommended procedures for counting colonies and reporting colony-forming units (CFU) on membrane filters (MF) and standard pour and spread plates.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Keywords

calculating results; counting colonies; membrane filter methods; pour plate methods; reporting results; rounding off; significant figures; spread plate methods; verification of counts ;

ICS Code

ICS Number Code 07.100.20 (Microbiology of water)

Citing ASTM Standards

[Back to Top]