Intraperitoneal Colchicine and Hypotonic KCl for Enhancement of Abundance and Quality of Meiotic Chromosome Spreads from Hamster Testes

Abstract

Male meiotic chromosome spreads of the Syrian hamster (Mesocricetus auratus, 2n = 44) were prepared by introducing two modifications into the method of Evans et al. (Cytogenetics, 3: 289-94, 1964). The modifications were pretreatment of the intact animals with colchicine (4 mg/kg injected intraperitoneally) and the use of 0.563% KCl solution to cause swelling of the cells. In animals subjected to colchicine for 1 or 2 hr, there was a markedly increased yield of cells in 6rst meiotic metaphase. This increase was not present in animals subjected for 3 hr, but these animals showed a slight increase of cells in second meiotic metaphase. The use of hypotonic KCl resulted in much sharper chromosome definition than had previously been obtained with 1% sodium citrate solution