Section 864.9550 - Lectins and protectins(a)Identification. Lectins and protectins are proteins derived from plants and lower animals that cause cell agglutination in the presence of certain antigens. These substances are used to detect blood group antigens for in vitro diagnostic purposes.(b)Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 864.9 .45 FR 60648, Sept. 12, 1980, as amended at 63 FR 59226, Nov. 3, 1998