Three classes and four (sub)classes of rat immunoglobulins: IgM, IgA, Ige and IgG₁, IgG2a, IgG2b, IgG2c

Class or subsclass‐specific differences have been investigated in the monoclonal immunoglobulins produced by 184 secreting immunocytomas raised in the LOU/Wsl inbred strain of rats. Seven classes or subclasses of rat immunoglobulins were detected and the names IgM, IgA, IgE, IgG 1 , IgG 2a , IgG 2b and IgG 2c proposed for them. The sedimentation coefficients of rat IgG 1 , IgG 2a and IgG 2c were found to be respectively, 6.7, 6.4 and 6.7 S. Rat IgG 1 , IgG 2a and IgG 2c were found to cross‐react with antisera to human γ‐chains.