Foot-and-Mouth Disease Non-Structural Protein (3ABC) Antibody ELISA Detection Kit

Target and Hazard: Foot-and-mouth disease (FMD) is caused by foot-and-mouth disease virus (FMDV, genus Aphthovirus, family Picornaviridae) and affects cloven-hoofed animals including pigs, cattle, sheep and goats. It is a Class I animal disease in China and a WOAH-listed notifiable disease. Affected animals develop vesicles and erosions on the oral mucosa, hooves and teats, and young stock may die suddenly from myocarditis; spread is extremely rapid with high morbidity, and outbreaks require quarantine and stamping-out, severely affecting livestock production and international trade. During virus replication, non-structural proteins (NSP), including 3ABC, are produced; 3ABC is the key marker for distinguishing field-virus infection from inactivated-vaccine immunity.

Significance of Testing: Inactivated vaccines do not contain non-structural proteins, so 3ABC antibodies are produced only during virus replication, i.e. field infection. The kit is used for the differential diagnosis of field-virus infection in vaccinated pig, cattle and sheep herds, and is a core tool for identifying latently infected animals in FMD-free status programmes and eradication. Combined with structural-protein antibody testing, it gives a full picture of herd immunity and infection status.

Principle: Blocking ELISA: microplates are coated with recombinant 3ABC antigen, and NSP antibodies in the sample compete with a fixed amount of enzyme-labelled anti-NSP monoclonal antibody for the antigenic sites; the higher the sample antibody level, the weaker the colour development (the higher the blocking rate).

Performance and Applications: 96-well format; total assay time approximately 2–2.5 hours; read at 450 nm and interpreted by blocking rate, giving objective results suited to batch testing; storage at 2–8 °C. For field-infection differentiation and eradication monitoring by large farms, animal disease prevention and control institutions and third-party laboratories. Method: blocking ELISA | Samples: serum (pig/cattle/sheep) | Assay time: ~2–2.5 h | Reading: microplate reader at 450 nm, interpreted by blocking rate | Format: 96-well 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 such as the virus neutralisation test are subject to our internal QC report.