By Pauline Go

DNA is a long, string-like object that governs the inheritance of such physical characteristics as color of eyes, shape of nose and ears, stature, bone density and other human and animal traits. DNA testing requires minute samples from any body tissue having nucleated cells like samples of semen, hair, saliva and urine. DNA is highly resistant to normal degradation like the effects of time, and other physical intrusions like detergents, acids, salt, petrol and other bacterial contamination.

DNA testing is one of the most exciting fields of technological advances. It is now being used extensively as a tool in crime solving. DNA testing is being applied to long unsolved crimes where traces of DNA remain. In many cases men wrongly convicted for crimes of murder and rape are now being released with evidence that is more than conclusive.

Often a key piece of evidence or a murder weapon is found with DNA of different people mixed together. Hitherto it has almost been impossible to unravel the evidence. Now a software program is available that can isolate each individual DNA and make the appropriate match.

One of the most infamous cases where DNA testing might have been applied was that of President Bill Clinton. Despite all his protestations to the contrary, when faced with the possibility of a DNA test on a semen sample on Monica Lewinsky's dress, he succumbed and admitted to his affair.

DNA testing is being used by people interested in tracing their ancestry. The cost of DNA testing has now become affordable so more and more people are trying to trace their roots.