Chromosome Banding

**Semantic type:** Laboratory Procedure

**Definition:** The treatment of chromosomes to reveal characteristic patterns of horizontal bands. The banding patterns lend each chromosome a distinctive appearance so the 22 pairs of human non-sex chromosomes and the X and Y chromosomes can be identified and distinguished without ambiguity. Banding also permits the recognition of chromosome deletions (lost segments), chromosome duplications (surplus segments) and other types of structural rearrangements of chromosomes.