We, FDA, are providing you, establishments that make donor eligibility determinations for donors of human cells, tissues, and cellular and tissue-based products (HCT/Ps), with recommendations concerning the use of FDA-licensed nucleic acid tests (NAT) in donor testing for hepatitis B virus (HBV) deoxyribonucleic acid (DNA). We consider the use of FDA-licensed HBV NAT in testing HCT/Ps donors to be necessary to adequately and appropriately reduce the risk of transmission of HBV. The FDA-licensed HBV NAT can detect evidence of the viral infection at an earlier stage than the hepatitis B surface antigen (HBsAg) and total antibody to hepatitis B core antigen (anti-HBc tests). Therefore, we recommend the use of FDA-licensed HBV NAT, in addition to the use of licensed HBsAg and total anti-HBc Immunoglobulin G (IgG) and Immunoglobulin M (IgM), for testing donors of HCT/Ps for evidence of infection with HBV. 1 The draft guidance, when finalized, will supplement previous recommendations from FDA to HCT/P establishments concerning donor testing for HBsAg and total anti-HBc, in the document entitled “Guidance for Industry: Eligibility Determination for Donors of Human Cells, Tissues, and Cellular and Tissue-Based Products (HCT/Ps)” dated August 2007 (2007 Donor Eligibility Guidance).