21 CFR § 864.5220 - Automated differential cell counter.

---
identifier: "/us/cfr/t21/s864.5220"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 864.5220 - Automated differential cell counter."
title_number: 21
title_name: "Food and Drugs"
section_number: "864.5220"
section_name: "Automated differential cell counter."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "H"
subchapter_name: "MEDICAL DEVICES"
part_number: "864"
part_name: "HEMATOLOGY AND PATHOLOGY DEVICES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "21 U.S.C. 351, 360, 360c, 360e, 360j, 360 371."
cfr_part: "864"
---


# 864.5220 Automated differential cell counter.

(a) *Identification.* An automated differential cell counter is a device used to identify one or more of the formed elements of the blood. The device may also have the capability to flag, count, or classify immature or abnormal hematopoietic cells of the blood, bone marrow, or other body fluids. These devices may combine an electronic particle counting method, optical method, or a flow cytometric method utilizing monoclonal CD (cluster designation) markers. The device includes accessory CD markers.

(b) *Classification.* Class II (special controls). The special control for this device is the FDA document entitled “Class II Special Controls Guidance Document: Premarket Notifications for Automated Differential Cell Counters for Immature or Abnormal Blood Cells; Final Guidance for Industry and FDA.”

[67 FR 1607, Jan. 14, 2002]