Development of a highly sensitive bead-ELISA to detect bacterial protein toxins.
A highly sensitive sandwich enzyme-linked immunosorbent assay to detect bacterial toxins was developed. Fab' of anti-toxin IgG was conjugated with horseradish peroxidase by the maleimide method and tetramethylbenzidine was used as substrate. As the solid phase, a 6.5 mm diameter polystyrene bead was used and this was coated with the anti-toxin IgG. The entire assay could be completed within 3.5 hr. The sensitivity of this bead-ELISA was found to be quite high with various bacterial toxins: less than 20 pg/ml for thermostable direct hemolysin of Vibrio parahaemolyticus, less than 60 pg/ml for Shiga toxin, less than 20 pg/ml for VT2 (Shiga-like toxin II) of Escherichia coli, less than 200 pg/ml for heat-labile enterotoxin of E. coli, and less than 6 pg/ml for cholera enterotoxin.
D001426:Bacterial Proteins / Q000032:analysis; D001427:Bacterial Toxins / Q000032:analysis*; D004492:Edetic Acid; D004797:Enzyme-Linked Immunosorbent Assay; D005069:Evaluation Studies as Topic; D006460:Hemolysin Proteins / Q000032:analysis; D012710:Serum Albumin, Bovine
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D006460:Hemolysin Proteins; D012710:Serum Albumin, Bovine; D004492:Edetic Acid