FASEB Breakthroughs in Bioscience article. "Blood Safety in the Age of AIDS" examines the effects of the AIDS epidemic on the safety of the blood supply. Just as a pebble tossed in a lake sends out ripples that last long after the pebble sinks, the discovery more than a decade ago that the AIDS virus was in the blood supply is still having repercussions on research and transfusion practices. New screening tests for blood and new ways of using one's own blood during surgery are among the steps that have made transfusions much safer. Meanwhile, researchers continue tracking down new threats and devising ways to circumvent them.