DNA tests 'come of age'

By Rajan Chakravarty
BBC Delhi bureau

Latha Reddy and her husband know the role DNA played for them

The solving of a baby-swapping case in Hyderabad has helped raise the profile of DNA fingerprinting in India.

The baby-swapping case saw a mother reunited with her baby son after testing confirmed she was not the mother of the girl the hospital said was hers.

"DNA fingerprinting has finally come of age in India," says Dr Lalji Singh, head of the Hyderabad-based Centre for Cellular and Molecular Biology, India's state-of-the-art DNA fingerprinting laboratory.

Dr Singh says the technology is now both cheap and easily available in India.

In the southern city of Hyderabad alone, there are three centres for DNA fingerprinting.

More will come in the future, says Dr Singh, as people realise the usefulness and potential of the technology.

Lower costs

Today, DNA fingerprinting for one person costs 2,500 rupees ($53), with many ordinary members of the public beginning to use the technology, Dr Singh says.

In 1989 [DNA fingerprinting] took us two months... now we can do it in 18 hours

Dr Lalji Singh

"If it is maternity being tested, only a mother and child's samples will be tested and it will cost about 5,000 rupees. It is a technology for the common man."

Hyderabad mother Latha Reddy had given birth to a baby boy but four days later was handed over a baby girl by hospital authorities.

The 19-year-old farmer's wife is not familiar with the intricacies of DNA fingerprinting but knows the technology played a key role in getting her son back.

She has a wide smile on her face every time someone mentions the word DNA.

One test confirmed she was not the mother of the girl and a second that she was the mother of the boy, who was finally handed over to her by police.

Four people were taken into custody - three hospital workers and the father of the girl.

Another reason for the increased popularity of the technology is that it takes less than a day to get the test results.

What is DNA fingerprinting?

The structure of everyone's DNA is the same but every person has a different sequence of "base pairs"

Everyone has billions of "base pairs", making it too time-consuming to identify individuals

Instead, scientists look at common repeating patterns known to vary among individuals

They can then determine whether two samples are from related people

"When I handled the first DNA fingerprinting case in India in 1989, it took us two months of work in the lab to sort and match the samples and come up with the final report," says Dr Singh.

"Now we can do the same job in 18 hours."

In 2001, forensic experts at Dr Singh's centre took less than 24 hours to establish the identity of one of the dead passengers in a Taiwan plane crash by matching the victim's samples with the DNA profile of his parents.

However, Dr Singh has a word of caution for law enforcers who are keen on using DNA fingerprinting to combat crime.

"Unlike in the West, Indian policemen are not usually accompanied by forensic [officers] at crime scenes.

"Often key evidence is destroyed by untrained policemen before it is collected," says Dr Singh.

He wants policemen nationwide to be trained in the handling and collection of DNA evidence from the scene of a crime.