A simple, rapid, high-resolution chromosome technic for lymphocytes.

Phytohemagglutinin (PHA) stimulated lymphocytes were exposed to a hypotonic solution consisting of equal parts of 0.075 M 2-Mercaptoethanol and 0.075 M KCl, followed by addition of colcemid. The cells were fixed and washed in the usual manner. The slides then were subjected to trypsin-Giemsa banding. This method yields a high percentage of mitotic figures in prophase and prometaphase, ideal for high-resolution chromosome analysis.