Schematic diagram showed non-radioactive metabolic incorporation followed by azide-biotin or azide-Alex555 labeling, and biotin signals of proteins were detected by streptavidin-HRP by western blot. HPG is incorporated into newly synthesized proteins by metabolism and protein synthesis and the triazole conjugation between newly alkyne proteins labeled HPG and azide labeled either biotin or Alex555 via CuSO4 catalysis (A). (B-a) The detection of biotin signals from extracted total proteins labeled by labeling reaction. Normal culture medium was changed to replace DMEM free of L-methionine supplemented with HPG after pulse 4 hr, and proteins were extracted in each of group at various time points including 0, 4, 24 and 72 hr. (B-b) Biotin signals of total proteins were detected. 1: Normal culture condition group; 2: HPG plus anisomycin group; 3: HPG group. (B-c,d,e) Biotin signals of Bcl-2, MMP-9 and IgG were individually detected in the immunoprecipitate pulled down by primary antibodies via siRNA post-transfection followed by non-radioactive metabolic labeling. (B-f) Radioactive isotope 35S-methonine incorporated into synthesized IgG purified by immunoprecipitation was detected by autoradiography. 1: 35S-methonine treated human choriocarcinoma cell line BeWo group and then antibody against human IgG immunoprecipitated human IgG in extracted total proteins; 2: cycloheximide plus 35S-methonine treated BeWo group then antibody against human IgG immunoprecipitated human IgG in extracted total proteins; 3: 35S-methonine treated skin fibroblast and then antibody against human IgG immunoprecipitated human IgG in extracted total proteins.