TABLE 7.

Impact of modification of the washing medium on viability, electrophoretic mobility, and hydrophobicity of test organisms subjected to different cell preparation protocols

Organism	Treatment	% of reference value
		Viability		Electrophoretic mobility		Hydrophobicity
		H2O/NaCl (NaCl/NaCl)a	H2O/H2O (NaCl/H2O)	H2O/NaCl (NaCl/NaCl)	H2O/H2O (NaCl/H2O)	H2O/NaCl (NaCl/NaCl)	H2O/H2O (NaCl/H2O)
Carbon-limited strain SW8	5,000 × gb	100	100	100	100	81	71
	15,000 × gc	100	100	122	100	75	219
	Freeze-drying	—d	—d	—d	—d	—d	—d
	Air drying	100	100	100	100	30	31
	MATH	100	49	100	100
Nitrogen-limited strain SW8	5,000 × gb	86	100	100	100	72	86
	15,000 × gc	100	100	100	100	59	304
	Freeze-drying	—d	—d	—d	—d	—d	—d
	Air drying	100	100	100	100	39	39
	MATH	100	100	100	100
E. coli	5,000 × gb	100	100	26	100	115	152
	15,000 × gc	100	100	194	100	100	67
	Freeze-drying	—d	—d	—d	—d	—d	—d
	Air drying	100	100	81	100	82	0
	MATH	100	100	321	100
S. epidermidis	5,000 × gb	100	100	163	123	86	100
	15,000 × gc	100	100	2,305	114	100	100
	Freeze-drying	—d	—d	—d	—d	—d	—d
	Air drying	100	100	273	4,925	100	100
	MATH	100	100	142	2,911

^aWashing medium/resuspension medium (washing medium/resuspension medium with which the reference value was obtained). 

^bCentrifugation at 5,000 × g. 

^cCentrifugation at 15,000 × g. 

^dThe bacterial cells used for XPS analysis were not washed in the NaCl solution.