COMPETITIVE ELISA OF BOVINE LACTOFERRIN WITH BISPECIFIC MONOCLONAL-ANTIBODIES

A mouse hybrid-hybridoma, HH1-4-3, secreting IgG(1), class bispecific antibodies to bovine lactoferrin (bLF) and horseradish peroxidase (HRP O), was established previously, The competitive enzyme-linked immunoso rbent assay (ELISA) of bLF using the HH1-4-3 culture supernatant was n ot sensitive enough to measure bLF concentration in biological fluids, To improve the sensitivity of the competitive ELISA, we fractionated the bispecific antibodies by antigen affinity column chromatography. A column immobilized with bLF adsorbed 60% of the antibodies of the HH1 -4-3 supernatant, and the amount of antibodies adsorbed on a column im mobilized with HRPO was less than 5%. The competitive ELISA of bLF usi ng the affinity purified bispecific antibodies through an HRPO-immobil ized column chromatography showed a good standard curve at bLF concent rations of 10 ng/ml to 100 mu g/ml.