TABLE 2.

CFDA/SE staining efficiency for different bacteria

Organism	Staining efficiency (%)	Comments
Gram-negative organisms
Acinetobacter johnsonii	98 ± 4	Moderately bright staining but high background fluorescence
Alcaligenes eutrophus	61 ± 27	Faint to moderately bright staining
Comamonas sp. strain DA001	99 ± 5
Cytophaga pectinovora	100 ± 0	Some CFDA/SE-positive cells are not DAPI positive
Enterobacter aerogenes	98 ± 5
Erwinia herbicola	98 ± 5	Some very faint staining
Escherichia coli BL	100 ± 0	Some very faint staining; some CFDA/SE-positive cells are not DAPI positive
Flavobacterium odoratum	100 ± 0	Very good staining, some variability
Klebsiella sp. strain 1PC	100 ± 0	Bright staining
Pseudomonas cepacia	100 ± 0	Faint staining but still visible
Pseudomonas fluorescens	<10	Very faint staining
Pseudomonas putida	<10
Pseudomonas sp. strain LB300	<10	Very faint staining
Pseudomonas sp. strain To11A	100 ± 0	Faint staining but still visible
Rahnella aquatilis BFB	100 ± 0	Moderately bright staining; some CFDA/SE-positive cells are not DAPI positive
Sphingomonas capsulata	100 ± 0	Even staining; some CFDA/SE-positive cells are not DAPI positive
Gram-positive organisms
Arthrobacter globiformis	100 ± 0	Very good staining; cells are more visible with CFDA/SE than with DAPI
Bacillus subtilis	100 ± 0	Some variable staining and high background fluorescence
Micrococcus luteus	100 ± 0	Very bright staining; some CFDA/SE-stained cells are not stained with DAPI
Paenibacillus polymyxa FER-02	100 ± 0	Uniform; some CFDA/SE-stained cells are not stained with DAPI
Rhodococcus rhodochrous	99 ± 5	Generally uniform staining
Streptomyces albus	<10	Very few cells are stained
Unidentified low-G+C-content strain SO-B2	100 ± 0	Very bright staining
Unidentified low-G+C-content strain SO-9	100 ± 0
SO-S10	100 ± 0