21 CFR §864.4400

1. (a)Identification. Enzyme preparations are products that are used in the histopathology laboratory for the following purposes:
   1. (1)To disaggregate tissues and cells already in established cultures for preparation into subsequent cultures (e.g., trypsin);
   2. (2)To disaggregate fluid specimens for cytological examination (e.g., papain for gastric lavage or trypsin for sputum liquefaction);
   3. (3)To aid in the selective staining of tissue specimens (e.g., diastase for glycogen determination).
2. (b)Classification. Class I (general controls). This device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.