Advances in donor screening and blood testing have dramatically improved blood safety in recent years. All blood collected at American Red Cross blood centers nationwide-which comprises approximately half of the nation's blood supply-is tested at one of nine National Testing Laboratories (NTLs). Technicians perform various tests on collected blood, including nucleic acid testing, a promising investigational technique.

As part of the donation process, at least three sample tubes of blood are collected, labeled and sent to one of the NTLs, all of which are highly standardized to meet rigorous standards. When the blood samples arrive, they are centrifuged to separate the plasma/serum, or liquid portion of the blood, from the red cells. The laboratory technicians also use the blood sample to determine the donor's blood type.

Using nationally standardized procedures, trained technicians perform at least 11 different tests on each sample of blood. Every unit of blood is screened for infectious diseases such as HIV, syphilis and hepatitis B and C, as well as for unexpected antibodies that might cause a transfusion reaction in some people.

Each American Red Cross blood donation also undergoes nucleic acid testing (NAT), an investigational testing method used to detect both HIV-1 and hepatitis C before the body has begun to produce antibodies. NAT testing at the American Red Cross and most other blood collection centers across the country is being done under an Investigational New Drug (IND) application submitted to the Food and Drug Administration (FDA). Preliminary results (American Red Cross NAT testing began in April 1999) suggest that the test may be more sensitive than any other screening method.

Within 18 hours of submitting the blood samples to the NTL, test results are sent back to the American Red Cross Blood Services Region where the collection took place, and any blood that does not pass all lab tests is destroyed. The donors of those unacceptable units are provided supplemental testing from the National Confirmatory Testing Laboratory (NCTL) and National Transfusion Transmitted Disease Laboratory (NTTDL). The donor's physician may use the supplemental test results to manage the donor's health concerns.