CFR > Title 21 - Food and Drugs > CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES > SUBCHAPTER F—BIOLOGICS (parts 600 to 680) > PART 640—ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS > SUBPART B—Red Blood Cells (§640.10 to §640.17) > 640.14—Testing the blood.