Analysis for the preparation of the immunogen for the production of polyclonal antibody against small subunit p50 of human DNA pol δ.

<p><b>A:</b> Agarose gel electrophoresis. M, DNA marker in bp; Lane 1, a selected colony of pGEX-5X-3-p50 digested with <i>Bam</i>HI and <i>Eco</i>RI. <b>B:</b> Coomassie Blue stained SDS-PAGE analysis for the purification of GST-p50 protein on glutathione-Sepharose 4B column. The lysates (BC), flow-through (FT), and eluted fractions were analyzed on 12% SDS-PAGE followed by Coomassie Blue staining. Protein maker is indicated in lane M as kDa. The position of GST-p50 protein is indicated by an arrow. <b>C:</b> Coomassie Blue stained SDS-PAGE analysis for release of non-tagged p50 by Factor Xa. Lane 1-4: fractions of released p50; Lane 5: the beads containing GST and unreleased p50 after digestion reaction. <b>D:</b> Coomassie Blue stained SDS-PAGE analysis for the peak fractions of released p50 protein further purified on Mono Q column.