[Code of Federal Regulations]
[Title 9, Volume 1]
[Revised as of January 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 9CFR113.43]

[Page 614]
 
                  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. 113.43  Detection of chlamydial agents.

    The test for chlamydial agents provided in this section shall be 
conducted when such a test is prescribed in an applicable standard 
requirement or in a filed Outline of Production.
    (a) The yolk sac of 6-day-old chicken embryos shall be injected. 
Three groups of 10 embryos shall be used sequentially.
    (1) The inoculum for each embryo in the first group shall consist of 
0.5 ml of a mixture of equal parts of the seed virus with phosphate 
buffered saline that may contain Streptomycin, Vancomycin, Kanamycin, or 
a combination thereof. Not more than 2 mg/ml of each antibiotic shall be 
used.
    (2) On the 10th day postinoculation, the yolk sac of viable embryos 
shall be harvested, pooled, homogenized as a 20 percent suspension in 
phosphate buffered saline antibiotic diluent, and 0.5 ml of the mixture 
injected into the second group of chicken embryos. This process shall be 
repeated for the injection of the third group of embryos using the yolk 
sacs of viable embryos from the second group.
    (3) For each of the three passages, embryo deaths occurring within 
48 hours of injection shall be disregarded, except that if more than 
three such deaths occur at any passage, that passage shall be repeated.
    (b) If one or more embryo deaths occur at any passage after 48 hours 
postinjection, the yolk sacs from each of the dead embryos shall be 
subcultured into 10 additional embryos. If one or more embryo deaths 
again occur due to chlamydial agents, the Master Seed Virus is 
unsatisfactory for use to produce vaccine.

[44 FR 58899, Oct. 12, 1979]