Figure 1. Escherichia coli (E.coli) O157:H7 Quantified Bacterial DNA Standards (STX1 and STX2 genes). 2 μL& of Norgen's Escherichia coli(E.coli) O157:H7 Quantified Bacterial DNA Standards (STX1 and STX2 genes) and serial dilutions (colored curves) were used in a 20 μL E coli O157:H7 -specific PCR reaction using Norgen's 2X PCR Master Mix (#28007). Utilizing Norgens' STX-1 and STX-2 specific TaqMan Primers/Probes a set of reactions was set up for detecting the STX1 (Shiga-like toxin) gene and another for detecting the STX2 gene. The real-time PCR reactions were 10 μL master mix, 2 μL Primer/Probe mix, 2 μL of Quantified Bacterial DNA Standard, and 6 μL of nuclease free water, and were performed on a Bio-Rad CFX Real-Time PCR System. No template controls with water were also performed (Black curves). Norgen's E coli O157:H7 Quantified Bacterial DNA showed consistent amplification down to 20 copies/μL.