Complement binding immunoglobulin the classical pathway is -
IgM is paicularly effective at complement activation by binding to C1. IgG activates the classical pathway of the complement system, a cascade of immune protein production Ref: Ananthanarayan & Parker's textbook of microbiology 9th edition pf:98
IgG & IgM
IgG & IgA
IgG & IgD
IgD & IgE
Immunology