---
kind: "unit"
title: "21"
title_heading: "Food and Drugs"
key: "chI/subchF/part660"
level: "part"
label: "Part 660"
heading: "Additional Standards for Diagnostic Substances for Laboratory Tests"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/21/chI-subchF-part660"
sections_count: 31
---

# Part 660 — Additional Standards for Diagnostic Substances for Laboratory Tests

Title 21 C.F.R. — Food and Drugs › Chapter I — Food and Drug Administration, Department of Health and Human Services › Subchapter F — Biologics

## Contents

- [Subpart A — Antibody to Hepatitis B Surface Antigen](/cfr/21/chI-subchF-part660-subpartA.md)
- [Subpart B — Subpart B [Reserved]](/cfr/21/chI-subchF-part660-subpartB.md)
- [Subpart C — Blood Grouping Reagent](/cfr/21/chI-subchF-part660-subpartC.md)
- [Subpart D — Reagent Red Blood Cells](/cfr/21/chI-subchF-part660-subpartD.md)
- [Subpart E — Hepatitis B Surface Antigen](/cfr/21/chI-subchF-part660-subpartE.md)
- [Subpart F — Anti-Human Globulin](/cfr/21/chI-subchF-part660-subpartF.md)