SmithKline Bio-Science Laboratories has announced a new test to identify AIDS virus antibodies in blood that it says can reduce the number of inconclusive tests for evidence of the deadly disease.

Known as Hivagen, the new test greatly reduces the chances of false positive readings, which are already uncommon under current testing procedures for acquired immune deficiency syndrome, a spokesman for the Philadelphia-based company said.

"This test is a quantum leap forward in AIDS testing," John Mills, chief of infectious diseases at San Francisco General Hospital, said in a statement released by SmithKline.

Mills performed clinical trials on the value of Hivagen as a replacement for the Western blot assay, the standard test for blood samples.

False positive readings, even though they represent a small fraction of tests, have become more common because AIDS antibody testing has become more common.

Like the blood tests currently in use, the Hivagen test uses proteins found in the AIDS virus to detect the presence of antibodies, substances produced by the immune system of the infected person. If a blood specimen contains such antibodies, they bind to the viral proteins and cause a color change.

But unlike other tests, the proteins in the Hivagen are manufactured synthetically, using genetic engineering techniques, rather than from cultured virus preparations.