In a new guidance document, the FDA announced that hepatitis B surface antigen (HBsAg) assays, used to detect the presence of hepatitis B infection in donations of human blood and blood components, should have a capability of detecting at least 0.5ng HBsAg/mL.

The agency is asking manufacturers to implement this recommendation by Jan. 31, 2008.

The recommendation follows advice given at a 2001 Blood Products Advisory Committee meeting, the guidance says. It applies to assays used to test whole blood and blood components, including source plasma and source leukocyte donations, and to establishments using HBsAg assays.

The guidance: “Adequate and Appropriate Donor Screening Tests for Hepatitis B; Hepatitis B Surface Antigen (HBsAg) Assays Used to Test Donors of Whole Blood and Blood Components, Including Source Plasma and Source Leukocytes.”