Fig. 3

SDS-PAGE analysis of inclusion bodies samples from different BL21 (DE3) strains induced with IPTG for 40 h at 20 °C. Lanes: M, molecular mass standard; 1, BL21 (DE3) (without plasmid); 2, BL21-NULL; 3, BL21-00; 4, BL21-01; 5, BL21-02; 6, BL21-03; 7, BL21-04; 8, BL21-05; 9, BL21-06.10 μg of total protein was loaded on a 12% SDS-PAGE gel. a These nine strains were induced with 0.2 mM IPTG for 40 h at 20 °C. b These nine strains were induced with 1.0 mM IPTG for 40 h at 20 °C. c Quantification of inclusion bodies protein bands in a by grayscale. d Quantification of inclusion bodies protein bands in b by grayscale. The grayscale value of the inclusion bodies protein bands from the non-fusion expression (namely, S-) was set to 1