What is the fact of Molecular Biology on which DNA fingerprint is based?
DNA fingerprint, the method of individual identification using DNA, is based on the fact that the DNA of every individual (with exception of identical twins and individual clones) having nucleotide sequences exclusive to each individual.
Although normal individuals of the similar species have the same genes in their chromosomes, every individual has dissimilar alleles and even in the inactive portions of the chromosomes (heterochromatin) there are differences in nucleotide sequences between individuals.