A simple, artificial-membrane feeding method for the radio-isotope labelling of Aedes aegypti polypeptides in vivo.

An artificial feeding unit has been designed and constructed to feed laboratory-bred Aedes aegypti with a radio-isotope (35S), so that the mosquitoes' polypeptides can be labelled in vivo. In the unit, a piece of Parafilm M barrier film is stretched over the bottom, outer surface of a polystyrene Petri dish, to create a small gap in which the mixture of blood and radio-isotope is placed. Warm water is placed in the dish, to keep the blood at about 37 degrees C. When such units were placed on net-covered rearing cages, almost all (80%-90%) of the female mosquitoes in the cages took bloodmeals from them. When checked by polyacrylamide-gel electrophoresis and autoradiography 1 h after feeding had begun, the blood-fed mosquitoes were found to have radio-labelled polypeptides. The unit is simple, easy to handle, disposable and can be used to offer small blood samples (>or=50 microl) to Ae. aegypti and, presumably, other mosquito species.