Sodium : Potassium Ratios in Insect Cell Culture and the Growth of Cockroach Cells (Blattariae: Blattidae)1

Abstract

Efforts to culture cockroach cells in media currently in use for Lepidoptera failed until the Na:K molar ratio was reversed, with sodium made 10× the concentration of potassium. With this alteration, cells grew out from several tissues of cockroaches. Cells grew out continuously for as long as 156 days in the original cultures of oviduct from Blattella germanica (L.). Fat body and an unidentified tissue adhering to malpighian tubules also produced cellular outgrowths for shorter periods. An extensive comparison of basal salt solutions which serve for insect cell cultures indicates the importance of agreement of the Na:K ratios of the culture fluids with the ratios of the blood, which in turn are correlated with phytophagous or carnivorous food habits.