Staff Reporter

DNA chip, if developed, will help establish the identity of individual

HYDERABAD: Human genome sequencing programme has led to development of a technology for developing Deoxyribonucleic Acid (DNA) chip, which will help establish the identity of an individual in criminal cases.

"If and when the DNA chip is developed, it will become simple and fast to establish match of biological sample found at the crime scene and DNA of the suspect with that of the chip," said Director of Centre for Cellular and Molecular Biology (CCMB) Lalji Singh.

"This will be the ultimate technique based on the comparison at the total genome level," he said during the Dr. Y. Nayudamma Memorial Lecture on 'Science of establishing individual identity: Past, present and future' at the Administrative Staff College of India on Thursday.

Genetic fingerprinting

Presence of repetitive DNA provided the basis to discriminate humans at an unprecedented level and 'genetic fingerprinting' gained broad applications in forensic casework, analysing genetic diversity in a population and monitoring cell line identity. It was also used in agriculture, wildlife conservation, paternity and maternity disputes, establishing identity of missing children, identifications in rape, murder, bodies, etc.

Tracing the growth of science to establish identities for investigating crime, Dr. Singh said fingerprints were used in the 19th century for the first time in the world in India by British Administrator William Herschel to prevent swindling of funds by soldiers.

Though a scientific or genetic explanation for having dissimilar fingerprints between human beings was not yet known, it gained acceptance because the probability of two people having identical fingerprints is next to impossible in comparison with world population.

Yet, there were cases in United States where persons with similar fingerprints surfaced, he said. Other than fingerprints, forensic scientists analysed blood groups and others that are protein based and hence, likely to get degraded by the time samples reach the lab.

Big discovery

Hence, discovery of DNA fingerprinting by Alec Jeffreys of United Kingdom in 1985 came as a big blessing to them. That is because DNA was stable, can be isolated from even a fossil, DNA pattern of an individual was the same in every tissue and does not change with age, said Dr. Singh.