title: Colony counting on hydrophobic grid-membrane filters.
abstract: A device to facilitate manual scoring of hydrophobic grid-membrane filters (HGMF) is described. Variations in scores were generally less than 2.5% between 41 analysts from six laboratories, who, using the apparatus, scored a set of five specimen HGMF in different ways, and there was good agreement between scores from positive and negative grid-cell counts by each analyst. A scoring procedure for use in routine microbiological analysis, suitable for HGMF at various degrees of saturation, is recommended.
mesh_terms: D001431:Bacteriological Techniques / Q000295:instrumentation*; D004926:Escherichia coli / Q000254:growth & development; D005374:Filtration / Q000295:instrumentation