Color Banding

In the early 1970s, a number of chromosome banding techniques were developed which produced reproducible transverse bands of different lengths along human chromosomes. These techniques included Q-banding, a fluorescent banding technique discovered by Caspersson in 1969; G-banding, proposed in 1971 by both Sumner and Seabright; and R-banding, introduced by Dutrillaux and Lejeune in 1971 (1 –4 ). Today conventional G-banding induced by either pretreatment with hot salt solutions or proteolytic enzymes has remained the gold standard in chromosome identification.