25 August 2011

Sperm cannot last more than 98 hours, says DNA expert...

Australian DNA expert Dr Brian McDonald told the High Court in the Sodomy II trial today that he was puzzled as to how sperm could still be retrieved 98 hours after a complaint of sodomy.

Testifying in Anwar Ibrahim's trial, McDonald (right) went on to criticse chemist Dr Seah Lay Hong for not doing the necessary check of swiping the sample on a receptacle for a sperm count.

In the first six to eight hours after ejaculation, he said, there would be a high level of sperm.

"After eight hours, the number of sperm cells recedes, and that is what literatures say," the witness added in reply to defence counsel Ram Karpal Singh.

Ram: The sample was sent to the chemist's lab after 98 or 99 hours. What sort of density can we expect in such sperm?


McDonald: The literature suggests a one-plus sperm after 56 hours, and it would be a low sperm count. In this case, it was kept another 48 hours at room temperature. I would say any sign of sperm would not exist at all.


Ram: In your literature readings, would you find a sperm sample after such hours?


McDonald: The finding of sperm in such a sample is inconsistent in the history of literature. It would ring alarm bells as to how this is possible. I would! And this would suggest (the sample could have been fresh), rather than it being old.


Earlier, the fourth defence witness was also questioned on the how the sample retrieved from the alleged victim, Mohd Saiful Bukhari Azlan, should be kept.

Sample kept in case officer's office for 48 hours

He said it should be air-dried and freezed to prevent the spread of bacteria on the sample.

Ram: What is the temperature which you say is suitable to freeze?

Dr McDonald: You must put samples in a freezer of minus 20 degrees Celcius. If this is not done, it will encourage bacteria growth and affect the cells. If it is kept at room temperature, there will be overgrowth of bacteria."

Saiful's sample, which was retrieved after 56 hours, was kept in the air-conditioned office of case investigating officer Supt Jude Blacious Pereira. It was then handed over to the Chemistry Department some 48 hours later.

McDonald also said there was a need to record the movement of evidence, what he referred to as the chain of evidence.

"Proper documentation of the movement of the evidence is good practice," he said, adding that failure to follow such a procedure may result in not getting accreditation.

"This has to be continuously be monitored at all times," he said.

The trial resumes tomorrow with Ram continuing with the examination of McDonald

source:malaysiakini

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