Cytogenetics--in color and digitized.

Cytogenetics is the genetic analysis of cells, a discipline that has flourished since the chromosome-banding techniques introduced in 1969 by Torbjorn Caspersson and Lore Zech first provided a simple and inexpensive way to gauge the number and assess the structural integrity of chromosomes. Chromosome banding (see Figure 1A) is probably the most commonly performed genetic test: it is used about 500,000 times each year in North America (most laboratories use G-banding, named after the German chemist Gustav Giemsa). It is used prenatally and postnatally to screen for the presence of constitutional chromosomal aberrations associated with birth defects, as well as for . . .