TABLE 1.

Regression analysis of model gene concentrations versus hybridization signal ratios from microarray hybridization [log (R′) = α log (f_x/f_λ) + β]^a

Model gene	Coefficient of determination (r2)	α, regression coefficient (slope)	β, constant (y-intercept)
nirS	0.97	0.63**	1.33**
nahA	0.96	0.66**	1.50**
O-antigen biosynthesis	0.86	0.48**	0.76*

^aAsterisk, P < 0.05; double asterisk, P < 0.001.