title: Colostral IgA, IgG, and IgM-IgA fractions as fluorescent antibody for the detection of the coronavirus of transmissible gastroenteritis.
abstract: Colostrum from sows and gilts inoculated with virulent transmissible gastroenteritis virus was fractionated into the 3 major immunoglobulin classes, IgA, IgG, and IgM-IgA fractions, by chromatographic and gel-filtration procedures. Each fraction was assayed for purity with rabbit anti-porcine serum and rabbit monospecific anti-porcine IgG, anti-porcine IgA, and anti-porcine IgM. These analyses showed that the IgG and IgA fractions were pure. The IgM fraction contained some IgA in the polymeric form and was designated the IgM-IgA fraction. Each Ig was assayed for virus-neutralizing activity on swine testes cells by the plaque-reduction method before and after conjugation with fluorescein isothiocyanate. On the basis of activity per milligram of protein, the virus-neutralizing titers were 1:641, 1:44, and 1:6.8 for the IgA, IgG, and IgM-IgA fractions respectively; the fluorescent antibody titers were 1:31.3, 1:0.1, and 1:15.6, respectively, for the same Ig.
mesh_terms: D000818:Animals; D003126:Colostrum / Q000276:immunology*; D003332:Coronaviridae / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D007070:Immunoglobulin A / Q000302:isolation & purification*; D007071:Immunoglobulin A, Secretory / Q000302:isolation & purification*; D007074:Immunoglobulin G / Q000302:isolation & purification*; D007075:Immunoglobulin M / Q000302:isolation & purification*; D008297:Male; D009500:Neutralization Tests; D013552:Swine / Q000276:immunology*; D005760:Transmissible gastroenteritis virus / Q000276:immunology*
chemical_list: D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D007075:Immunoglobulin M