147.8—Procedures for preparing egg yolk samples for diagnostic tests.

The following testing provisions may be used for retaining the classification U.S. M. Gallisepticum Clean under § 145.23(c)(1)(ii)(C) and § 145.33(c)(1)(ii)(C), for retaining the classification U.S. M. Synoviae Clean under § 145.23(e)(1)(ii) (b) and § 145.33(e)(1)(ii) (b ), and for retaining the classification U.S. H5/H7 Avian Influenza Monitored under § 146.23(a), § 146.33(a), and § 146.44(a) of this chapter.
(a) Under the supervision of an Authorized Agent or State Inspector, the eggs which are used in egg yolk testing must be selected from the premises where the breeding flock is located, must include a representative sample of 30 eggs collected from a single day's production from the flock, must be identified as to flock of origin and pen, and must be delivered to an authorized laboratory for preparation for diagnostic testing.
(b) The authorized laboratory must identify each egg as to the breeding flock and pen from which it originated, and maintain this identity through each of the following:
(1) Crack the egg on the round end with a blunt instrument.
(2) Place the contents of the egg in an open dish (or a receptacle to expose the yolk) and prick the yolk with a needle.
(3) Using a 1 ml syringe without a needle, aspirate 0.5 ml of egg yolk from the opening in the yolk.
(4) Dispense the yolk material in a tube. Aspirate and dispense 0.5 ml of PBS (phosphate-buffered saline) into the same tube, and place in a rack.
(5) After all the eggs are sampled, place the rack of tubes on a vortex shaker for 30 seconds.
(6) Centrifuge the samples at 2500 RPM (1000×g) for 30 minutes.
(7) (i) For egg yolk samples being tested to retain the U.S. M. Gallisepticum Clean and U.S. M. Synoviae Clean classifications, test the resultant supernatant for M. gallisepticum and M. synoviae by using test procedures specified for detecting IgG antibodies set forth for testing serum in § 147.7 (for these tests the resultant supernatant would be substituted for serum); except that a single 1:20 dilution hemagglutination inhibition (HI) test may be used as a screening test in accordance with the procedures set forth in § 147.7.
(ii) For egg yolk samples being tested to retain the U.S. H5/H7 Avian Influenza Monitored classification, test the resultant supernatant in accordance with the requirements in § 146.13(b).

Code of Federal Regulations

Note: For evaluating the test results of any egg yolk test, it should be remembered that a 1:2 dilution of the yolk in saline was made of the original specimen.

Code of Federal Regulations

[50 FR 19900, May 13, 1985; 63 FR 3, Jan. 2, 1998, as amended at 71 FR 56333, Sept. 26, 2006]