An analytical method, described herein, is based on differences in the primary structure of immunoglobulins and their subclasses. This method is independent of the supply of specific antisera, is simple and inexpensive to perform, and is fully reproducible. The distribution of subtypes of IgG and IgA resembled published results from immunological studies. Finding of differences in the distribution of subclasses of IgG proteins in patients with light-chain disease or in the absence of M-protein is of special interest.
Kochwa S, Makuku E, Frangione B. Chemical Typing of Immunoglobulins and Their Subtypes. Arch Intern Med. 1975;135(1):37-39. doi:10.1001/archinte.1975.00330010039005