PRECIPITATION TEST 1 69 



(subcutaneously or intravenously) rabbits with lo cc. of filtered 

 defibrinated horse blood (or serum) every other day five or six 

 times. At the end of this time draw blood from the rabbit, 

 allow it to clot kept on ice, remove the serum and filter, where- 

 upon the reagent is ready for use. Express and extract (in saline 

 solution) the juice from the meat suspected to contain horse meat, 

 filter and keep on ice until wanted for use. To the filtrate thus 

 prepared add a few drops of the equinized rabbit serum. If 

 cloudiness and slight whitish precipitate forms it constitutes a 

 positive test, proving conclusively that the suspected meat is 

 horse meat or contains horse meat. Only raw fresh meat re- 

 sponds to this test. Heating destroys the action of the reagent. 

 Inoculating rabbits with the defibrinated and filtered blood 

 serum of various animals, as of hog, domestic fowl, deer, dog, 

 bear, etc., and testing in the manner outlined in the following 

 method by Dr. Karl F. Meyer of the State University of Cali- 

 fornia, the meat of the responding animal may be identified. 



The Precipitin Test for the Detection of Horse and Deer 

 Meat and for Meat Adulterations in General 



The method can be used for fresh, dried, frozen, pickled, raw 

 and smoked, but not for boiled, meat. The meat may not be 

 heated above 6o°-'jo° C. for the biologic test. 



For the tests are needed : 



a. Specific antisera (anti-horse or deer precipitin serum; pre- 

 cipitin) . 



b. Aqueous extract of the meat to be identified (precipitinogen). 

 I. Antisera.^ — The sera must be specific and highly active 



against the meat protein to be determined. Rabbits are in- 

 jected subcutaneously, intravenously or intraperitoneally with 

 serum, defibrinated blood or extract of the fat free meat. The 

 best results are obtained by inoculating fresh serum intravenously. 

 The sera for injection can readily be obtained from_ abattoirs 



