Chromosomal banding pattern is the pattern of colors formed when the chromosome is exposed to certain specific dyes.
These dyes do a color reaction with a special repetitive sequence of base pairs.
When the normal pattern is not obtained
there may be two reasons
1. Chromosomal injury
2. Chromosomal aberration.
In injury certain part is either deleted or shifted to somewhere else
in aberration chromosome is normal but its sequence is got changed.
So its certain that is has got great diagnostic value.
But it fails
in case of point mutation or certain others.
This banding pattern is also helpful in preliminary diagnosis of a suspect in any crime but most of the judiciaries do not assure of its results.