Table 2

Quantitation of S. aureus genomic DNA (gDNA) by real time PCR

MDA

S. aur gDNA

Probe

Average Ct

SEM (±)

N

100 ng

proS

17.8

0.03

N

10 ng

proS

22.1

0.05

N

1 ng

proS

24.6

0.03

N

0.1 ng

proS

27.7

0.06

N

0.01 ng

proS

31.7

0.26

N

0 ng

proS

U

U

(N)

0.01 ng

proS

35.4

0.85

(Y)

0.01 ng

proS

16.9

0.05

Triplicate samples of isolated S. aureus genomic DNA were assayed by qPCR; the calculated average threshold critical cycle (Ct) values are provided, as is the standard error. Each sample concentration gave a highly reproducible result; the data shown are using the proS probe, but equivalent results were obtained using lysS. Pre-treatment of S. aureus gDNA by MDA resulted in a massive reduction in Ct, indicating a massive amplification of template. In MDA control lacking the DNA polyermase, Ct actually slightly increased, due to dilution of the starting material. 0 ng of gDNA (negative control) gave no detectable signal (Ct undetermined, represented as "U" above).

Kathju et al. BMC Research Notes 2010 3:259   doi:10.1186/1756-0500-3-259