Expression and purification of a functional human hepatitis B virus polymerase

Figure 2 Induction optimization of hepatitis B virus polymerase expressed in Escherichia coli. Total lysate samples of Escherichia coli transformants after different induction times were blotted on to nitrocellulose membranes. Hepatitis B virus polymerase (HBV-Pol) expression level was determined by anti-Xpress antibody. A: 8-h induction sample showed the strongest signal; B: HBV-Pol expression level at different temperatures was determined by anti-Xpress. Sample from 18°C showed the highest expression level. Preliminary expression data showed that no obvious signal was detected in samples induced at temperatures < 18°C, therefore, previous values for duration and temperature for induction were selected for this study.