The use of DNA fingerprinting has grown rapidly and, to date, no State court has denied the admissibility of properly collected and tested evidence. FBI guidelines for collecting and preserving samples emphasize the need to photograph the evidence, collect it, and store it carefully by allowing it to air dry, then sealing and freezing it. As large a sample as possible should be collected. While DNA has resulted in several major convictions, there has been some concern over the admissibility of DNA evidence supplied by commercial laboratories that may not adhere to accepting matching techniques. However, most experts agree that DNA testing is a reliable procedure, although it is not applicable to all biological specimens and cannot replace other classical serological tests in obtaining trial evidence.