TABLE 1.

Mean cycle threshold (C_T) values for replicates of prepared BD GeneOhm StaphSR assay positive- and negative-control reagents frozen at −70°C for 3 weeks, 9 weeks, and 18 weeks^a

Reconstituted reagent	Mean CT ± SD following −70°C storage for:
	3 wks	9 wks	18 wks
Positive controlb	35.15 ± 0.29	35.20 ± 0.24	35.40 ± 0.22
Negative controlc	33.87 ± 0.43	34.10 ± 0.40	34.59 ± 0.16

^aC_T values for negative-control material are indicative of internal-control amplification.

^bThe mean C_T value ± standard deviation for freshly prepared positive-control reagent (22 determinations) was 34.67 ± 0.48.

^cThe mean C_T value ± standard deviation for freshly prepared negative-control reagent (22 determinations) was 34.63 ± 0.32.