TABLE 1.

Quantitation of CFTR mRNA by semiquantitative RT-PCR of mouse small intestine

Infection status	n	Mean titera	SDb of titer
Uninfected	7	174	104
15-min infected	2	182	NDc
15-min mockd	2	191	ND
1-h infected	8	210	258
1-h mock	5	151	244
2-h infected	5	350	279
2-h mock	3	231	210

^aTiter was determined by preparing cDNA from 3 μg of total RNA and then PCR amplifying different dilutions of the cDNA. The titer is the cDNA dilution at which no PCR product is detectable.

^bSD, standard deviation.

^cND, not done.

^dmock, mock-infected intestinal loops were injected with diluent only instead of bacterial suspension.