DEVELOPMENT OF A SENSITIVE AND SPECIFIC TIME-RESOLVED FLUOROMETRIC IMMUNOASSAY FOR THE BOVINE ACUTE-PHASE PROTEIN HAPTOGLOBIN (HP)

Haptoglobin (Hp) is recognised as a major acute phase protein in the b ovidae and its presence in serum is used as an indicator of inflammati on. A mouse monoclonal antibody (1D9) specific for bovine Hp was label led with a lanthanide (Eu) chelate and used to develop a competitive i mmunoassay. This competitive immunoassay allowed direct measurement of Hp in serum and was validated for intra- and interassay coefficients of variation (below 8%). Cross-reactivity with other serum proteins wa s measured (less than 0.1%) and limits of detection for Hp in serum we re established for adult male (0.344 mu g/ml) and adult female cattle (1.589 mu g/ml). The immunoassay was compared with an established hapt oglobin-haemoglobin binding assay.