[Code of Federal Regulations]
[Title 21, Volume 7]
[Revised as of April 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR610.20]

[Page 76]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 610_GENERAL BIOLOGICAL PRODUCTS STANDARDS--Table of Contents
 
          Subpart C_Standard Preparations and Limits of Potency
 
Sec.  610.20  Standard preparations.


    Standard preparations made available by the Center for Biologics 
Evaluation and Research shall be applied in testing, as follows:
    (a) Potency standards. Potency standards shall be applied in testing 
for potency all forms of the following:

                               Antibodies

Botulism Antitoxin, Type A.
Botulism Antitoxin, Type B.
Botulism Antitoxin, Type E.
Diphtheria Antitoxin.
Histolyticus Antitoxin.
Oedematiens Antitoxin.
Perfringens Antitoxin.
Antipertussis Serum.
Antirabies Serum.
Sordellii Antitoxin.
Staphylococcus Antitoxin.
Tetanus Antitoxin.
Vibrion Septique Antitoxin.

                                Antigens

Cholera Vaccine, Inaba serotype.
Cholera Vaccine, Ogawa serotype.
Diphtheria Toxin for Schick Test.
Pertussis Vaccine.
Tuberculin, Old.
Tuberculin, Purified Protein Derivative.
Typhoid Vaccine.

                            Blood Derivative

Thrombin.

    (b) Opacity standard. The U.S. Opacity Standard shall be applied in 
estimating the bacterial concentration of all bacterial vaccines. The 
assigned value of the standard when observed visually is 10 units. The 
assigned value of the standard when observed with a photometer is (1) 10 
units when the wavelength of the filter is 530 millimicrons, (2) 10.6 
units when the wavelength of the filter is 650 millimicrons, and (3) 9 
units when the wavelength of the filter is 420 millimicrons.

[38 FR 32056, Nov. 20, 1973, as amended at 41 FR 10429, Mar. 11, 1976; 
41 FR 18295, May 3, 1976; 49 FR 23834, June 8, 1984; 55 FR 11013, Mar. 
26, 1990]