5.1 This test method describes a procedure for producing spore suspensions of C. difficile ATCC 700792, C. difficile ATCC 43598, or C. difficile ATCC 43599. The spore suspensions may be used in antimicrobial efficacy testing, or other laboratory testing requiring C. difficile spores. A spore crop is considered acceptable if the titer is >8 log₁₀ spores/mL, purity of 95%, and is resistant to 2.5M HCl after 10 min of exposure (see Test Method E2839).

1.1 This test method is designed to propagate spores of Clostridium difficile using liver broth.

1.2 It is the responsibility of the user of this test method to determine whether Good Laboratory Practices are required and follow when appropriate.

1.3 This test method should only be performed by those trained in microbiological techniques.

1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 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.