These test methods provide information on the dimensional stability and wetting characteristics of autoclaved membrane filters. Excessive dimensional changes caused by autoclaving a constrained membrane filter could crack the filter, rendering it useless. Increased hydrophobicity, due to autoclaving would result in an increased time to filter a liquid sample.1.1 These test methods deal with tests to determine the autoclavability of membrane filters.1.2 These test methods are applicable to all membrane filters. Either Test Method A, Test Method B, or both, may be utilized to assess the autoclavability of membrane filters.