1. Scope
1.1 This guide covers an example of a method that measures the changes in a population
of aerobic microorganisms within a specified sampling time when antimicrobial test
materials are present.
1.1.1 Several options for organism selection and growth, inoculum preparation, sampling
times and temperatures are provided.
1.1.2 When the technique is performed as a specific test method, it is critical that the
above mentioned variables have been standardized.
1.1.3 Antimicrobial activity of specific materials, as measured by this technique, can vary
significantly depending on variables selected.
1.1.4 Test Method E2783 may be referenced as an example of using fixed conditions and set
variables to evaluate antimicrobial efficacy of water-miscible compounds.
1.1.5 This guide serves as a general teaching document for evaluating the antimicrobial
activity using a variety of conditions to offer the flexibility needed in test conditions
to cover a broad range of microorganisms and test substances.
1.1.6 It is important to understand the limitations of in vitro tests, especially comparisons of results from tests performed with different parameters.
As an example, test results of microorganisms requiring growth supplements or special
incubation conditions may not be directly comparable to organisms evaluated without
those stated conditions.

