Foot-and-Mouth Disease Virus Type A ELISA Antibody Detection Kit (Competitive Method)

Target and Hazard: Foot-and-mouth disease is one of the most dangerous contagious diseases of cloven-hoofed animals, and type A, together with type O, is among the main serotypes circulating in China. Ruptured vesicles on the feet and mouth readily become secondarily infected, shedding of the hoof horn causes long-term lameness and inability to feed, milk yield in dairy cows falls abruptly, and young animals often die suddenly of myocarditis. China classifies the disease as a Class I animal disease, and outbreaks are handled by quarantine, culling and area control; the indirect losses considerably exceed the direct ones.

Significance of Testing: This kit targets type A FMDV, detecting type A-specific antibodies in serum for herd-level immune-qualification surveys after type A vaccination. Its competitive format allows a single enzyme-labelled monoclonal antibody to cover bovine, ovine and porcine sera, avoiding systematic bias from species-specific secondary antibodies and making results directly comparable between species within a herd or across farms. It provides quantitative support for decisions on booster vaccination and timing, and when combined with NSP (3ABC) antibody testing it further allows field infection to be differentiated.

Principle: Competitive ELISA: microplates are coated with type A FMDV-specific antigen; sample antibodies compete with a fixed amount of enzyme-labelled monoclonal antibody for the binding sites, so the more antibody present the weaker the colour, with antibody levels determined from the percent inhibition (PI).

Performance and Applications: 96-well format, approximately 40–44 samples per plate including positive and negative controls; total assay time about 2–2.5 hours; read at 450 nm and interpreted by percent inhibition, well suited to centralised testing of large sample batches; store at 2–8 °C, protected from light, shelf life 12 months. For immune monitoring of type A FMD on commercial farms, pre- and post-introduction antibody screening and epidemiological investigation by disease control institutions. Method: competitive ELISA | Samples: serum (cattle/sheep/pig) | Assay time: ~2–2.5 h | Reading: microplate reader at 450 nm, interpreted as percent inhibition (PI) | Format: 96-well plate, ~40–44 samples per plate | Storage: 2–8 °C, protected from light; shelf life 12 months | Note: sensitivity, specificity, limit of detection, intra-/inter-assay CV and agreement with reference methods are subject to our internal QC report.