Application of Methods for Mammalian Chromosome Spreads to the Cells of Cestodes

Tapeworm cells obtained by physical maceration between ground-glass surfaces are incubated for 3 hr in Hanks' balanced salt solution (BSS) supplemented with colchicine to a concentration of 10-⁴ M. After washing in BSS, the cells are incubated for 10 min in 1/4 strength BSS then centrifuged 10 min. Fixation of the intact button of cells (or alternatively, by squirting the cells directly into the fixative) in Carnoy's alcohol-chloroform-acetic acid (6;3:1) for 30 min follows, and cells, dispersed and washed in the fixative, are flattened by dropping the suspension on clean, water-wet slides which are then air-dried and stained with Giemsa diluted 1 ml;47 ml with distilled water to which 2 ml of buffer—M/15 KH₂PO₄, 32 ml, mixed with M/15 Na₂HPO₄, 68 ml—is added. After staining 15 min and washing in distilled water, slides are air-dried and mounted with resin. Well separated and well stained chromosomes have resulted.