Radiometric Method for the Detection of Coliform Organisms in Water

Abstract

A new radiometric method for the detection of coliform bacteria in water has been described. The method is based on the release of 14CO2 from [14C]lactose by bacteria suspended in growth medium and incubated at 37 C. The evolved 14CO2 is trapped by hyamine hydroxide and counted in a liquid scintillation spectrometer. The method permits the detection of 1 to 10 organisms within 6 h of incubation. Coliform bacteria suspended in water for several days recover from starvation and may be quantitated by the proposed method. Bacteria from water samples may also be concentrated by filtration through membrane filters and detected by the radiometric assay.