A solid-phase ELISA for human galactosyltransferase.

Monospecific rabbit anti-human milk galactosyltransferase antibodies were used to develop a solid-phase enzyme-linked immunosorbent assay (ELISA) for the human milk enzyme. The assay was based on competition with galactosyltransferase-phosphatase conjugate. The detection limit of the standard curve was 30 ng/ml. Galactosyltransferase was quantified in dialyzed milk samples by ELISA with variation coefficients of less than 7.7% and between 6.8 and 18.8% within and between assays, respectively. The average content was 61 +/- 19 microgram/ml. The assay proved suitable for quantitation of partially purified enzyme preparations in body fluids.