Figure 1.

Sensitivity of TaqMan multiplex in QuantStudio. Ten-fold serial dilutions of Ames (Panels (A), (B) and (C)) or control plasmid carrying GI4 from Bcbva (Panel (D)) were tested in triplicate to establish the limit of detection of each primer pair and corresponding probe. The B. anthracis genome specific marker Ba-1 was consistently detected at 100 fg of genomic DNA, with sporadic amplification at the 10-fg level (Panel (A)). capB (Panels B) and lef (Panels (C)) targets were detected with as little as ~2 and 9 GE of pXO2 and pXO1, respectively, but could not be amplified at a lower 10-fold dilution (Panels (B) and (C)). GI4 was reliably detected with at least 17.7 GE of pGI4 (Panel (D)). The standard curve plots displayed R² and slopes values as follows: Ba-1, R² = 1, slope = −3.3793; capB, R² = 0.9986, slope = −3.3337; lef, R² = 1, slope = −3.3519; GI4, R² = 0.9996, slope = −3.1776.