Identification of Mr variants of prolactin with monoclonal antibodies

Monoclonal antibodies ( QB01 and 1200) prepared against human prolactin (hPRL) have helped define a variant form of the hormone. This variant is of apparently higher molecular mass (26 kDa) than the predominant form of the hormone (24 kDa) and its presence does not appear to be species-restricted. The demonstration of the 26 kDa form of hPRL in fresh pituitary tissue and amniotic fluid suggests it may retain some specific function.