Use of monoclonal antibodies for radioimmunoassay of water buffalo milk progesterone

Abstract

SummaryIn order to standardize a radioimmunoassay of milk progesterone as a routine method for confirmation of oestrus and diagnosis of pregnancy in water buffalo, monoclonal antibodies against progesterone were produced. Hybridomas were prepared by fusing spleen cells from a Balb/c mouse immunized with progesterone 11α-hemisuccinate–bovine serum albumin conjugate with the mouse myeloma cell line NS-1. Thirty wells out of 94 secreted anti-progesterone antibodies. Of the ten independent hybridomas derived, one (AF65) was suitable for the quantification of milk progesterone by radioimmunoassay. The tracer used in the assay was progesterone-11α-hemisuccinate ([2-125I]iodohistamine). The sensitivity of the assay was 50 pg/tube. The mean progesterone concentration at oestrus was 0·8±0·2 ng/ml increasing to 8·5±0·8 ng/ml 24 d later in pregnant animals.