Enzyme immunoassay of VASP-P. A microwell plate is coated with a specific mouse monoclonal antihuman VASP antibody that binds to VASP to be measured. Then, a peroxidase-coupled mouse anti-human VASP-P monoclonal antibody binds to phosphorylated serine 239 antigenic determinant of VASP. The bound enzyme peroxidase is then revealed by its activity on the TMB substrate over a predetermined time. After stopping the reaction, absorbance at 450 nm is directly related to the concentration of VASP-P initially contained in the sample.