Figure 1.

Expression of DNA polymerases B1 and Y1 in S.solfataricus cells. Quantitative western blots showing detection of the polymerases in cell lysates including standards with different amounts of purified proteins. The S.solfataricus cell extract was prepared as described in Materials and Methods. Lanes 1–5, purified proteins applied at 15, 30, 60, 120 and 240 ng/lane; lanes 6–8, S.solfataricus total cell extract applied at 5, 10 and 15 µl/lane. The chemiluminescence values shown beneath the lanes were expressed as the sum of the intensities of the pixels inside the volume boundary manually selected around each band per area of a single pixel, as described in Materials and Methods. The intensity values obtained for the amounts of 15, 30 and 60 ng (lanes 1–3) were used to construct a linear regression curve for each protein. From these titration curves, the protein concentration values were extrapolated for the lanes loaded with 15 µl of total cell extract.