An improved diluent for rubella hemagglutination and hemagglutination-inhibition tests.
Rubella hemagglutinating (HA) antigen was prepared in BHK-21 tissue as 5% cell suspensions and from unconcentrated and 20x concentrated infected supernatant fluids. In some instances, unconcentrated fluids were treated with Tween 80 and ether; cell suspensions were treated with ether alone. Preparations were tested for HA activity in dextrose-gelatin-Veronal (DGV) buffer solutions; 0.85% NaCl; Sorenson's phosphate-buffered saline, pH 7.2; and a diluent of 0.9% NaCl, 0.1% CaCl(2) (anhydrous), and 0.1% MgSO(4).7H(2)O. HA titers were consistently two- to fourfold higher in the saline with added Ca(++) and Mg(++) than in DGV. Hemagglutination-inhibition titers of paired human sera were the same in either diluent. It is suggested that the interaction between rubella HA antigen and the red cells of young (less than 1-day-old) chicks may be at least partially ion dependent and that titers are enhanced by increased quantities of divalent cations.
D000818:Animals; D000941:Antigens; D002021:Buffers; D002118:Calcium / Q000494:pharmacology; D002645:Chickens; D046508:Culture Techniques; D006385:Hemagglutination Inhibition Tests; D006386:Hemagglutination Tests; D006801:Humans; D008274:Magnesium / Q000494:pharmacology; D012409:Rubella / Q000175:diagnosis*; D012412:Rubella virus / Q000276:immunology
D000941:Antigens; D002021:Buffers; D008274:Magnesium; D002118:Calcium