Figure 3.

Expression and purification of Der f 28. (A) SDS-PAGE analysis of the protein expressed from the pET-44a(+)-Der f 28 recombinant plasmid in E. coli BL21 cells. Lane M, Protein Marker; Lane 1, E. coli BL21 transformed with pET-Der f 28 without IPTG induction; Lane 2, E. coli BL21 transformed with pET-Der f 28 with IPTG induction; (B) the peak figure of recombinant protein Der f 28 purified by molecular sieve chromatography. Longitudinal axis (mAu) for protein absorption peak; horizontal axis (mL) for volume; blue curve for protein absorption peak; gray curve for conductance value; (C) SDS-PAGE analysis of the final purified r-Der f 28 from E. coli BL21 cells. Lane M, Protein Marker; Lane 1, r-Der f 28 purified by molecular sieve chromatography.