**4.7 Slide inhibition test-slide agglutination test (SIT-SAT)**

This method is developed for the detection of CPV-2. SIT is an antibody typing system based on the ability of viral antibodies to bind with the virus and prevents the virus from binding to RBC. SAT is used for antigen detection by serially diluting the clinical sample and then incubating it with a fixed amount of RBC containing virus surface receptors. The virus particles in the sample bind to the RBC and form a lattice that can be seen visually [60].

### **4.8 Enzyme-linked immunosorbent assay (ELISA)**

It is an enzyme-based immunoassay involving antigen–antibody interactions to screen a large number of samples at a time. Recombinant VP2 protein-based indirect ELISAs has been developed to detect and quantify antibodies against CPV-2. Novel polyclonal antibody-based antigen capture ELISA using rabbit anti-CPV hyperimmune sera as capture antibody and guinea pig anti-CPV hyperimmune sera as detector antibody has been also developed. IgY-based ELISA comprising of the chicken egg yolk-derived has been developed for the detection of both antigen and antibodies. Different commercial ELISA kits are currently available for CPV-2 antigen and antibody detection [61].
