Drosophila squashes

Tchen et al. (1985) squashed complete etherized Drosophila flies on nylon or nitrocellulose membranes. The membranes were placed on a filter which was sandwiched between two plastic sheets cut from heat-sealable plastic bags. The flies were squashed one by one using a spatula (photocopies after squashing for further localization of specific flies). The plastic sheets were then discarded and the membrane layered successively for 2 min on Whatman 3MM paper (soaked with 10% SDS or H2O), twice for 5 min on 0.5 M NaOH (or KOH)/2.5 M NaCl and finally three times 2 min on NaOAc (pH 5.0). After neutralization, large fragments (wings, etc.) were removed with forceps and the blots dried for 30 min at room temperature and baked in a vacuum at SO C for at least 1 h. Here, best results were obtained with Pall Posidyne membranes. 

For some purposes it is desirable to hybridize probes to chromosomes spread on a microscope slide, rather than in intact tissues. Squashes of Drosophila... 

Hayashi, S., GiUam, I. C., Delaney, A., and Tener, G. M. (1978) Acetylation of chromosome squashes of Drosophila melanogaster decreases the background in autoradiographs from hybridization with I-labelled RNA. J. Histochem. Cyto-chem. 36,677-679. 

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