RAISING LARGE QUANTITIES OF DROSOPHILA FOR BIOCHEMICAL EXPERIMENTS

Mass cultures of Drosophila have been used in the preparation of a variety of cellular components, including RNA, proteins, DNA, and nuclei. This chapter describes the system used to rear and maintain a population of about 400,000 flies capable of producing 100 g of embryos a day. The minimal requirements for growth of the flies are simple and can be easily met. However, to obtain maximum yield of embryos, proper environmental conditions should be maintained: humidity of 70%, temperature of 25oC, and a constant 24-hr light-dark cycle. The adult flies are fed yeast food. A single strip of yeast paste is spread on a grape plate and the whole plate is placed inside the fly cage. Although the grape plate is probably fed on lightly, its predominant purpose is to stimulate egg laying on its surface as a consequence of the attractive aroma and high surface humidity. The washed embryos can be used immediately for experimental purposes or to continue the population; alternatively, they can be frozen at –80°C for future experiments. © 1994 Elsevier Science Publishers, B.V.