CFR›Title 21›Chapter I›Part 660›21 CFR Part 660 Subpart A Citation21 CFR Part 660 Subpart AContainsSections § 660.1–§ 660.6CorpusDaily eCFRDisplayed edition2026-08-04Last updated2026-08-04 Subpart A—Antibody to Hepatitis B Surface Antigen Sections § 660.1 § 660.1 Antibody to Hepatitis B Surface Antigen. § 660.2 § 660.2 General requirements. § 660.3 § 660.3 Reference panel. § 660.4 § 660.4 Potency test. § 660.5 § 660.5 Specificity. § 660.6 § 660.6 Samples; protocols; official release. Authority21 U.S.C. 321, 331, 351, 352, 353, 355, 360, 360c, 360d, 360h, 360i, 371, 372; 42 U.S.C. 216, 262, 263, 263a, 264.