Section 660.22 - Potency requirements with reference preparations(a)Potency requirements. Products for which reference Blood Grouping Reagents are available shall have a potency titer value at least equal to that of the reference preparation.(b)Reference preparations. Reference Blood Grouping Reagents shall be obtained from the Food and Drug Administration, Center for Biologics Evaluation and Research, Reagents and Standards Shipping, 10903 New Hampshire Ave., Bldg. 75, Rm. G704, Silver Spring, MD 20993-0002, and shall be used as described in the accompanying package insert for determining the potency of Blood Grouping Reagents.53 FR 12764, Apr. 19, 1988, as amended at 67 FR 9587 , Mar. 4, 2002; 70 FR 14985 , Mar. 24, 2005; 80 FR 18093 , Apr. 3, 2015