title: Validation of flow cytometry for rapid enumeration of bacterial concentrations in pure cultures.
abstract: Flow cytometry was investigated as a rapid detection and counting method for bacteria in pure cultures. A simple two-parameter detection scheme was employed: particle size was measured by forward angle light scatter and nucleic acid content by fluorescence of the DNA/RNA-binding dye ethidium bromide. The technique gave results that correlated exceptionally well with conventional plate counting for four species of bacteria, and concentrations in the range 10(2) to 10(7) cfu/ml. Cytometric counts were obtained in a few minutes, as compared with 2 d required for the plate counts. Under ideal conditions, each bacterial species examined exhibited a characteristic 'signature' on the cytometer, which could be explained by its known properties and morphology.
authors.affiliation: Department of Chemical Physics, AFRC Institute of Food Research, Norwich Laboratory, UK.
authors.forename: A C
authors.initials: AC
authors.lastname: Pinder
authors.forename: P W
authors.initials: PW
authors.lastname: Purdy
authors.forename: S A
authors.initials: SA
authors.lastname: Poulter
authors.forename: D C
authors.initials: DC
authors.lastname: Clark
mesh_terms: D000333:Aeromonas / Q000032:analysis / Q000254:growth & development; D015169:Colony Count, Microbial / Q000379:methods*; D004269:DNA, Bacterial / Q000032:analysis; D013293:Enterococcus faecalis / Q000032:analysis / Q000254:growth & development; D005434:Flow Cytometry; D007778:Lactobacillus / Q000032:analysis / Q000254:growth & development; D008027:Light; D011551:Pseudomonas fluorescens / Q000254:growth & development; D012542:Scattering, Radiation
chemical_list: D004269:DNA, Bacterial