Fig. 1
Expression and immunological characteristics of rMSNOX protein. A SDS-PAGE analysis of expression and purification of rMSNOX protein. Lane M: protein ladder; lane 1: cell lysates of E. coli BL21 containing empty vector; lane 2: total cell lysates of recombinant strain E. coli BL21 (pET28a-MSnox); lane 3: supernatant of total cell lysates of recombinant bacteria; lane 4: purified His-tagged MSNOX protein; lane 5: purified His-tagged MSFBA protein. The gels in this figure were cropped, and the original gel is presented in Supplementary Fig. S2. B Immunogenicity analysis of rMSNOX protein. Lanes1 and 2: western blot analysis of the purified rMSFBA and rMSNOX with rabbit anti-rMSNOX serum; lane 3 and 4: western blot analysis of the purified rMSFBA and rMSNOX with pre-immune rabbit serum. The blots were cropped from two blots, which are presented in Supplementary Fig. S3. Immunoreactivity and specificity analysis of rMSNOX, on the basis of western blot (C) and ELISAs (D). Lanes 1–5: chicken sera positive for various MS isolates (MS WVU1853, MS JS1, MS HB1, MS SD1, and MS SH1); lanes 6–11: chicken sera positive for various MG isolates (MG Rlow, MG 08, MG 013, MG FBH, MG SGN, and MG SS); lanes 12–19: sera positive for other avian pathogens (MI, E. coli O1/O2/O78, SPG, PM, STA, NDV, IBDV, and IBV); lane 20–22: field MS-negative sera (FN-1, FN-2, and FN-3); 23: negative serum from SPF chickens. Blots were cropped from different gels and are divided by white space (Supplementary Fig. S4). The samples derived from western blotting experiments, and the gels/blots were processed in parallel. Significant differences between OD450 nm values of chicken sera positive for various MS isolates and other avian pathogens were analyzed with unpaired T-test in GraphPad Prism 6