TABLE 2.

Validation of microarray-based expression profiles by real-time RT-PCR

Gene	Product/function	Antibiotica	Condition (MIC, time [min])	Relative expression levelb at:		Validationc
				Microarray	Real-time PCR
rplF	Ribosomal protein L6	Cm	0.25×, 15	3.8	7.3	Yes
		Em	0.25×, 15	1.5	3.9	Yes
		Em	0.25×, 60	0.6	0.7	Yes
		Gm	0.25×, 5	2.2	4.3	Yes
		Gm	0.25×, 60	0.5	0.3	Yes
rbsB	Ribose ABC transporters; ribose-binding protein	Cm	0.25×, 15	3.8	4.4	Yes
		Em	0.25×, 15	0.5	0.3	Yes
		Em	0.25×, 60	1.7	1.6	Yes
		Gm	0.25×, 15	0.4	0.4	Yes
groES	Class I heat shock protein	Cm	0.25×, 15	0.3	0.3	Yes
		Cm	0.25×, 60	0.3	0.4	Yes
		Em	0.25×, 15	0.5	0.3	Yes
		Em	0.25×, 60	1.6	0.1	No
		Gm	0.25×, 60	3.9	9.8	Yes
clpP	Class III heat shock protein	Cm	0.25×, 15	0.6	0.6	Yes
		Gm	0.1×, 60	2.0	2.3	Yes
		Gm	0.25×, 60	3.8	4.0	Yes
		Gm	0.4×, 60	4.3	4.7	Yes
cspB	Cold shock protein	Cm	0.4×, 60	3.4	6.5	Yes
cspD	Cold shock protein	Em	0.25×, 15	2.9	4.4	Yes

^aCm, chloramphenicol; Em, erythromycin; Gm, gentamicin.

^bValues shown are the relative transcript levels of treated sample over untreated sample. The same RNA samples were used for both microarray and RT-PCR experiments. Values more than one indicate induction and values less than one indicate repression in the antibiotic-treated samples.

^c“Yes” indicates validation of microarray data of up- or downregulation.