During a war , the lost children were adopted by military personnel. Based on advanced blood test , they were later reunited with their parents. Name the technique used in this case & mention its scientific basis

DNA fingerprinting

Based on the fact that DNA of one individual is 90% identical to DNA of another individual but there is 10% difference. This 10% does not code for protein, RNA, and carries short sequences of 10 -100 nucleotide pairs. These specific sequences are tandemly repeated many times and are found at many places throughout the length of DNA. The no:of repeats is very specific in each individual  & it is inherited. Such polymorphic genetic loci are called Simple tandem repeats. The tandem repeats of short sequences are called Variable number tandem Repeats (VNTRs).