Validation of flow cytometry for rapid enumeration of bacterial concentrations in pure cultures.
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.
Pinder
A C
AC
Department of Chemical Physics, AFRC Institute of Food Research, Norwich Laboratory, UK.
Purdy
P W
PW
Poulter
S A
SA
Clark
D C
DC
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
D004269:DNA, Bacterial