TABLE 2.

Mean percentages of cells of a pair of S. aureus strains identified as polarized or depolarized following physicochemical treatments, staining with DiOC₂(3), and analysis by FCM^a

Sample	Mean ± SEM (%)
	S. aureus strain 1		S. aureus strain 2
	Depolarized	Polarized	Depolarized	Polarized
Live control	12.05 ± 2.14	84.05 ± 3.78	10.47 ± 3.74	87.60 ± 3.08
Heat-killed control	89.04 ± 4.48	7.01 ± 2.37	94.73 ± 1.18	7.46 ± 2.22
50°C	47.96 ± 2.08	46.90 ± 2.34	24.00 ± 2.39	67.98 ± 3.65
60°C	80.90 ± 3.71	14.26 ± 3.21	83.79 ± 3.24	7.21 ± 4.15
70°C	87.79 ± 3.11	7.43 ± 1.01	93.09 ± 3.02	10.18 ± 3.59
80°C	91.88 ± 0.62	2.26 ± 0.71	93.71 ± 0.59	2.92 ± 0.65
Freezing	43.01 ± 1.52	34.06 ± 2.26	69.97 ± 6.40	22.63 ± 3.90
Citric acid	80.96 ± 2.86	4.86 ± 3.02	83.03 ± 1.89	9.59 ± 0.73
Oxalic acid	49.35 ± 4.56	33.77 ± 4.20	77.43 ± 3.76	15.51 ± 1.84
NaCl	7.92 ± 2.87	89.45 ± 2.27	26.51 ± 8.14	63.29 ± 1.03
NaOH	85.07 ± 5.01	8.41 ± 3.56	50.46 ± 8.10	37.68 ± 0.60
CTAB	77.12 ± 4.18	0.00 ± 0.00	81.11 ± 1.24	0.00 ± 0.00

^aTreatments: live control, untreated stained cells; heat-killed control, cells exposed to temperatures of >95°C for 30 min to ensure complete loss of viability; freezing, cells frozen overnight and thawed at room temperature for 1 h before analysis. All of the following treatments were for 10 min: 50°C, heated to 50°C; 60°C, heated to 60°C; 70°C, heated to 70°C; 80°C, heated to 80°C; citric acid, exposure to 1% (wt/vol) citric acid solution; oxalic acid, exposure to 1% (wt/vol) oxalic acid solution; NaCl, exposure to 1% (wt/vol) NaCl solution; NaOH, exposure to 2.5% (wt/vol) NaOH solution; and CTAB, exposure to 0.5 mM CTAB.