DNA Testing at Its Prime:

A University of Virginia scientist uses technology to improve testing accuracy. Computer-assisted testing distinguishes the fathers from the non-fathers, and the criminals from the innocent.

By LaToya Gilbert

"But the glove didn't fit" was a popular slogan heard throughout the world when O.J. Simpson was found not guilty in 1995. Professor Rolf Benzinger remembers this story as he sits at his desk dressed in old jeans, a T-shirt, and a sun visor. It's all about "DNA sensitivity," he says as he props his feet up on the desk and crunches on a Hydrox cookie. Because of sensitivity--the component of DNA testing that detects testing errors--scientists are able to more accurately complete tests used in criminal trials. The same kind of error-reduced testing that freed O.J. Simpson is Benzinger's passion.

Benzinger, a microorganism specialist at University of Virginia, loves to discuss his research on DNA. And he knows what he's talking about. In 1991 he taught human genetics to FBI agents at the FBI academy run by U.Va. These classes taught background information and new techniques for DNA testing based on hair evidence. He also helped the FBI agents improve mitochondrial DNA testing, a genetic code.

In the past 10 years DNA testing has improved; it is used more frequently in paternity tests, rape cases, and murder cases because its results are now 99.9% accurate. Computers widely communicate information, store databases, and differentiate and compare DNA samples. With the use of electronic microscopes and computer-recorded data, scientists can more efficiently test evidence to avoid repeating data. These more accurate results are possible because "sensitivity has improved a millionfold," Benzinger says. Scientists have also found a way to repeat testing to increase accuracy--for example, a single hair provides enough genetic material to be tested 1000 times.

Repeat testing is significant for all DNA tests: paternity, murder, and rape. Repeat testing enhances the accuracy of sensitivity. The enhanced accuracy created by combining repeat testing and sensitivity ultimately creates a graph comparing samples. The graph gives side-by-side information of the victim and suspect or the mother, father, and child's DNA code. The code is read as a series of lines specific to each person's gene code.

DNA testing "cannot improve much more," Benzinger says. However, test costs, currently above $500, can be reduced, and improvements can be made in educating the public about DNA testing. For example, women must be told that in cases of rape they must "swab before washing or evidence will be lost." Because people are unaware of how DNA testing works, information can be altered or destroyed. Educational outreach is key to the future success of DNA testing. Scientists will be able to collect legitimate samples and victims will be able to ensure that scientists' tests are accurate through their own lawyer's testing.

DNA testing is not likely to change in the next five years. The minor difference will appear in the test subject; tests will be done on proteins rather than body fluids, blood, and hair. This will occur because tests on body fluids, blood, and hair are already structured to their most efficient potential. Therefore, scientists will search for alternate methods of determining DNA. Another change that will come about, to be lawyers will be more confident about doing DNA tests on their own. Because information on DNA testing will be better understand lawyers will be able to analyze those tests done by "experts."

Another important development is the use of Web sites that communicate DNA testing information to scientists. "Scientific improvements can be communicated worldwide to places like Australia and New Zealand," Benzinger says. "Though we have excellent databases, it just doesn't cut it if your testing is not up to speed," he says. Because DNA testing is done worldwide scientists must use the fastest method possible to communicate new information.

Because the accuracy of DNA testing is so important to the success of genetic/paternity testing and in court cases, it is imperative that scientists create the most efficient method of testing. Rolf Benzinger's goal is to make sure that testing is performed to its greatest potential and that people recognize the significance of its accuracy and how it can help them.

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