Insect Embryo Chromosome Techniques

Abstract

The whole-mount method for studying chromosomes of insect eggs is used; the eggs are caused to adhere to cover glasses, which are handled in racks especially designed for carrying large numbers. A basic and helpful change in the usual technique after fixation and before staining involves extraction of the material 1 hr to overnight with a 1:1 methanol-chloroform mixture to remove plasmal-reactive substances. Either leucobasic fuchsin or sulfonated azure A after acid hydrolysis may be used satisfactorily to stain the chromosomes.