Chromosomal Banding

R-banding is the reverse pattern of G bands so that G-positive bands are light with R-banding methods, and vice versa. R-banding involves pretreating cells with a hot salt solution that denatures DNA that is rich in adenine and thymine. The chromosomes are then stained with Giemsa. R-banding is helpful for analyzing the structure of chromosome ends, since these areas usually stain light with G-banding.

C-banding stains areas of heterochromatin, which is tightly packed and repetitive DNA. NOR-staining, where NOR is an abbreviation for "nucleolar organizing region," refers to a silver staining method that identifies genes for ribosomal RNA that were active in a previous cell cycle.