Comparison between five methods for the separation of IgM.

Five serum fractionation methods were examined with regard to their suitability for use in the demonstration of specific IgM antibodies. It was found that Protein A - Sepharose CL - 4B chromatography leads to higher IgM recovery than absorption with whole Staphylococcus aureus (58% as opposed to 40%). It is also cheaper, since this absorbent can be reused.

[Hemagglutination inhibition test for rubella virus: control of the removal of complete non-specific inhibitors].

A method showing whether the inhibitory activity of a serum, with a low rubella HAI titer, is due to specific antibodies, or to the incomplete removal of non-specific beta-lipoprotein inhibitors, is described. Serum absorption with Staphylococcus aureus removes over 95% of the IgG, and a smaller amount of the other Ig, beta-lipoproteins and albumin, whereas Staphylococcus epidermidis absorbs about 20% of all Ig, beta-lipoproteins and albumin. This means that a serum with anti-rubella IgG displays the same, or at most a slightly depressed HAI titer after absorption with S.

[Sensitivity of human and pigeon erythrocytes to rubella virus].

Human cord blood and adult red blood cells (rbc) and pigeon rbc were compared for sensitivity to rubella virus hemagglutination by a new method, consisting of the direct counting of free and aggregate red blood cells by using an hemocytometer chamber. With this method, more reliable than the "pattern test", hemagglutination is quantitated by the "aggregation index" (A.I.