[Code of Federal Regulations]
[Title 9, Volume 1]
[Revised as of January 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 9CFR113.37]

[Page 636-637]
 
                  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. 113.37  Detection of pathogens by the chicken embryo inoculation 
test.

    The test for detection of extraneous pathogens provided in this 
section shall be conducted when such a test is prescribed in an 
applicable Standard Requirement or in the filed Outline of Production 
for the product.
    (a) The biological product to be tested shall be prepared for use as 
recommended on the label, or in the case of desiccated vaccine to be 
used in poultry, rehydrated with sterile distilled water at the rate of 
30 ml per 1,000 doses.

[[Page 637]]

    (b) One volume of the prepared vaccine shall be mixed with up to 
nine volumes of sterile heat-inactivated specific antiserum to 
neutralize the vaccine virus in the product. Each lot of antiserum shall 
be demonstrated by virus neutralization tests not to inhibit other 
viruses known to be possible contaminants.
    (c) After neutralization, 0.2 ml of the vaccine-serum mixture shall 
be inoculated into each of at least 20 fully susceptible chicken 
embryos.
    (1) Twenty embryos, 9 to 11 days old, shall be inoculated on the 
chorio-allantoic membrane (CAM) with 0.1 ml, and in the allantoic sac 
with 0.1 ml.
    (2) Eggs shall be candled daily for 7 days. Deaths occurring during 
the first 24 hours shall be disregarded but at least 18 viable embryos 
shall survive 24 hours post-inoculation for a valid test. Examine all 
embryos and CAM's from embryos which die after the first day. When 
necessary, embryo subcultures shall be made to determine the cause of a 
death. The test shall be concluded on the seventh day post-inoculation 
and the surviving embryos (including CAM's) examined.
    (d) If death and/or abnormality attributable to the inoculum occur, 
the serial is unsatisfactory: Provided, That, if there is a vaccine 
virus override, the test may be repeated, using a higher titered 
antiserum.

[38 FR 29889, Oct. 30, 1973, as amended at 39 FR 21042, June 18, 1974]