MILK PROGESTERONE SENSOR FOR APPLICATION WITH DAIRY-CATTLE

A biochemical sensor for progesterone was developed and evaluated for its feasibility for measurement of milk progesterone concentration. The approach involved the attachment of progesterone antibodies to the surface of a 10 Mhz quartz crystal. Binding of progesterone to the antibodies increases the crystal's mass resulting in a proportional decrease in the crystal's natural frequency. Significant changes were observed in the natural frequency of crystals coated with antibodies consistent with changes in mass related to the attachment of progesterone, saturation of antibody binding sites with progesterone, and removal of progesterone. Operation of the crystal in liquid caused an increase in variation of the crystal's frequency and loss of crystal oscillation. This research illustrated the potential of this conceptual approach for measurement of progesterone in milk and highlighted several remaining challenges. © 1994 Silsoe Research Institute.