Chromosomal Banding Patterns Produced by Methyl Green-Pyronin Staining After Trypsin Treatment

Abstract

A method is described for producing banding pattern with methyl green-pyronin (MGP) stain in chromosomes of fibrosarcoma cells. 1) The stain was made by mixing equal volumes of 2% aqueous pyronin G, 2% aqueous methyl green, distilled water, and 0.1 M acetate Mer (pH 5.7). 2) Treatment with colcemide and hypotonic KCI (0.075 M) was performed u usual. 3) Metaphase chromosomes were prepared using the flame-drying technique and treated with 0.25% trypsin at 37 C for 45 to 90 seconda. Before staining, the slides were rid in PBS, in distilled water, and then were dipped in 0.05 M acetate buffer. 4) Chromosomes were stained for more than 20 minuta, rinsed in distilled water, and hot-air dried. satisfactory results were obtained in uncontracted metaphase chromosomes. MCP stain hm the advantage of permitting much longer trypsin treatment and staining time than the trypsin-Giemsa method while providing satisfactory banding pattern.