Immunochemical and related interactions with dextrans reviewed in terms of improved structural information.

Structurally diverse dextrans from Leuconostoc mesenteroides and related bacteria have been used extensively in fundamental immunochemical studies such as induction and characterization of anti-dextran antibodies, as well as in studies of their interaction with pneumococcal antisera, normal bovine serum, concanavalin A, dextran-binding myeloma immunoglobulins and hybridoma antibodies. The inherent lack of specificity of structural data obtained by POSA and general lack of insight into other limitations of these analyses has often led to inaccurate and superficial interpretations. Proper interpretation of past and future studies necessitates pointing out previous inadequacies of dextran structural data and detailing more recently acquired structural information on the dextrans. Unambiguous terminology has been achieved by a new system of linkage symbols that includes the designation of structural positions, such as (1----3; l)- and (1----3; b) as linear-chain and branch-point positions, respectively. Results of immunological studies are reviewed. Improved interpretations and correlations are made on the basis of structural data from MSA and several other techniques which have become available on the dextrans.