qRT-PCR of ex vivo Salmonella enterica in TLR4 minus/plus macrophage background

A major virulence factor in S. enterica is the pathogenicity island Spi2. The goal of the experiment was to determine the impact of the toll-like receptor 4 (TLR-4) on expression of Spi2 in S. enterica wild type (WT) and triple mutant strain (TMS) with deletions in SPI-1 TTSS, SPI-2 TTSS, flagella. The stain 14028 was used for the experiment. Cells were grown in a TLR-4 wildtype (plus) or deleted (minus) macrophage background. Total RNA was extracted and processed by qRT-PCR. Two strains (WT and TMS) grown under 2 conditions (TLR-4 wildtype (plus) or TLR-4 deleted (minus)) - total 4 samples were analyzed in the study. All PCRs were done in quadruplicates, located on the same PCR plate. For each quadruplicates the median value was calculated and used as a data point for further normalization. A set of controls was selected for all data sets using the following criteria: the data points for the controls should have Cp <40 and be present in all the samples.