ombs test).
Rabbit antisera to purified K or X chains were selected for their reactivity with both
Bence Jones proteins and myeloma proteins of the corresponding light chain type. Antisera
to purified normal IgG and to monoclonal Ig of the three main classes or their heavy
chains were selected for their ability to react both with the Fc fragment and with
nonidiotypic determinants located on the Fd segment. The selected antisera to ‘y, , a, K or X
chains were pooled and rendered monospecific by adsorption on suitable antigens coupled
to Sepharose 4B by cyanogen bromide. Specificity was carefully assessed by double diffusion
and, after labeling, by immunofluorescence staining of fixed smears of cells from
patients with myeloma or macroglobulinemia of known class and type and on living cells
of patients with CLL and immunodeficiency diseases. Antisera monospecific for the three
heavy-chain classes and the two light-chain types were used in all instances.