Banding pattern observed in human chromosomes by the modified BSG technique.

A successful modification of the BSG technique to reveal C and R bands simultaneously in human chromosomes is described. Conventional air dried preparations were treated first with 0.1 N HCl for 30 min at room temperature, then denatured in freshly prepared 3% aqueous solution of Ba(OH)2SH2O for 10 min at 50 degrees C. After rinsing, the slides were incubated for 1 h at 60 degrees C in 2 X SSC, and stained with Giemsa. The striking intense staining pattern could be observed in chromosome No. 19. The factors involved in the present technique were analyzed changing the concentrations of the reagents and the treatment time. It was evident that R, T and C bands correspond to a progressive destruction of the chromosome structure mainly by the Ba(OH)2SH2O solution.