Immunochemical analysis of cell supernatants and crystals.

(A) SDS-PAGE analysis of crystals formed in vitro by 8A4 cells and analyzed under nonreducing (lane 1) or reducing (lane 2) conditions; only polypeptides corresponding to immunoglobulin H and L chains were detected by Coomassie blue staining. (B) SDS-PAGE analysis under reducing conditions of antibodies purified from 8A4 (lane 1) and 8A4-NP1 (lane 2); Coomassie blue staining; molecular weight markers are indicated in kilodaltons. (C) Agar zone electrophoresis of serum from an 8A4 mouse (lane 1), an 8A4-NP1 mouse (lane 2), and the solubilized cryoglobulin precipitate obtained from 8A4-NP1 serum (lane 3); the upper arrow indicates serum albumin, and the bottom arrow marks the monoclonal cryoglobulin peak.