Comparison of flow cytometry and epifluorescence microscopy for counting bacteria in aquatic ecosystems

Flow cytometry was used to count bacterial cells from diverse origins: one strain of E. coli, one sample of lake water, and 18 samples of estuary water. To verify the accuracy and the precision of this technique, total bacteria counts made by flow cytometry were compared with counts by direct observation using epifluorescence microscopy. The results of this study showed that flow cytometry was a reliable technique for counting a mixture of bacteria in samples from aquatic ecosystems.