Figure 3. Agarose gel electrophoresis showing the effect of total soil DNA template concentrations on PCR product yields. PCR reactions were performed as described in methods section, taking a wide range (1 pg to 100 µg) of purified DNA as template from one rhizospheric soil sample (sampling site 1), using the universal conserved primers to amplify native bacterial species in the soil samples. Five µl of PCR product was applied on the gel. Lanes 2 through 11 contain 1 pg, 10 pg, 100 pg, 1 ng, 10 ng, 100 ng, 500 ng, 1 µg, 10 µg, and 100 µg DNA templates, respectively. Lanes 12 and 13 contain positive and negative control PCR products, respectively. Lane 1 and 14 contain molecular size marker in base pairs (1 µg low range DNA ruler, Bangalore Genei).