Sterol-free eukaryotic cells from continuous cell lines of insects

Three cell lines from Mamestra brassicae (Lepidoptera), one from Aedes albopictus (Diptera) and one from Sarcophaga peregrina (Diptera) were continuously cultured in a sterol-free medium and analyzed for sterol content. No sterols were found in any of the cell lines, whereas from cells cultured in a serum-containing medium, cholesterol was detected. This is the first instance of sterol-free animal cells.