The precipitin test in the detection of horsemeat

Abstract

Repeated inoculation of alum-precipitated serum by the intramuscular route has proved to be the method of choice in preparing high-level precipitating sera in rabbits. The antiserum so produced is non-specific, but by absorption with heterologous sera the specificity can be fully restored without reducing the titre of the homologous antibody. A high homologous titre of the antiserum is an advantage in meat identification work, as the meat-antigen titre is always many times lower than the corresponding serum-antigen titre. Sera of high antibody titre have higher sensitivity against homologous meats. Consequently such sera are more reliable than low-level antisera for detection of small amounts of adulteration with a foreign meat. The precipitin test is of little practical value for identification of cooked meat. Positive precipitations can be obtained with meats only which have not been heated at a higher temperature than 80°C. for not longer than 10 minutes. Unmelted fat can be used as an alternative source of material when no raw meat is available for species identification.