Abstract
The IgG M-components of 70 sera were quantitated by a paper electrophoretic method and by an immunochemical method with the use of an antiserum raised against purified polyclonal IgG. The results obtained by the two procedures were concordant and thereby showed that IgG M-components of different antigenic compositions can probably be quantitated by simple immunochemieal methods. Immunochemical determination of the total IgG content of sera containing IgG M-components by the Mancini technique agreed, both when the sera were assessed in their native and in their carbamylated form, with the immunochemical quantitation of Weeke. This indicates that different IgG M-components are immunochemically similarly altered by carbamylation.