[Code of Federal Regulations]
[Title 9, Volume 1]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 9CFR113.407]

[Page 766]
 
                  TITLE 9--ANIMALS AND ANIMAL PRODUCTS
 
  CHAPTER I--ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF 
                               AGRICULTURE
 
PART 113_STANDARD REQUIREMENTS--Table of Contents
 
Sec. 113.407  Pullorum antigen.

    Pullorum Antigen shall be produced from a culture of representative 
strains of Salmonella pullorum which are of known antigenic composition, 
high agglutinability, but are not sensitive to negative and nonspecific 
serum. Each serial shall be tested for purity, density, preservative 
content, sensitivity, homogeneity, and hydrogen ion concentration. A 
serial found unsatisfactory by any prescribed test shall not be 
released.
    (a) Purity test. Final container samples of completed product shall 
be tested for viable bacteria and fungi as prescribed in Sec. 113.26. 
In addition, each serial shall be free from extraneous organisms as 
determined by Gram staining and microscopic examination.
    (b) Nephelometric determination of bacterial density. The bacterial 
density shall be 80 15 times McFarland No. 1 
standard for stained antigen K's and 50 10 times 
McFarland No. 1 standard for tube antigen.
    (c) Preservative requirements. (1) The formalin content of Pullorum 
Stained Antigen K shall be 1.0 0.2 percent as 
determined by a colorimetric method.
    (2) The phenol content for Pullorum Tube Antigen shall be 0.55 
0.05 percent as determined by direct titration 
with a standardized bromide-bromate solution.
    (d) Sensitivity requirements. (1) Each serial of antigen shall be 
compared with a reference antigen of known sensitivity using positive 
and negative chicken serum. The manufacturers' recommendations for use 
on the accompanying label or package insert shall be followed. The 
recommended time limit specified for each antigen shall be carefully 
observed in the test.
    (2) A total of at least 12 serums shall be used. This shall include 
at least three definitely positive, at least three weakly positive, and 
at least six negative serums. At least three positive chicken serums 
diluted with negative chicken serum shall be used to further assay 
comparative sensitivity between test and reference plate antigens. All 
test antigens shall agree closely with the reference antigen. Tests in 
which variation of readings between the reference and test antigen would 
result in a different National Poultry Improvement Plan classification 
shall be regarded as unsatisfactory. No unsatisfactory tests among the 
six or more negative serums and not more than one unsatisfactory test 
among the six or more positive serums shall be permitted. All tests 
performed shall be included for evaluation of the sensitivity assay. In 
the event of an unsatisfactory test using positive serums, at least 
three additional definitely positive and three additional weakly 
positive serums shall be tested. If not more than one unsatisfactory 
test is obtained with the additional serums, the antigen shall be 
acceptable.
    (e) Homogeneity requirement. Antigens shall show no evidence of 
autoagglutination or unusual appearance such as the presence of flakes, 
specks, or a preponderance of filament forms. Microscopic examination 
shall be made in this determination.
    (f) Hydrogen ion concentration. The hydrogen ion concentration shall 
be determined with a pH meter which has been standardized with a pH 4.0 
buffer just prior to use. The pH of Pullorum Stained Antigen K shall be 
4.6 0.4. No pH level is specified for Pullorum 
Tube Antigen but after dilution as recommended for use, it shall have a 
pH of 8.2 to 8.5.

[39 FR 16857, May 10, 1974. Redesignated at 39 FR 25463, July 11, 1974, 
and amended at 40 FR 760, Jan. 3, 1975. Redesignated at 55 FR 35561, 
Aug. 31, 1990]