Protein L / Agarose

Protein L binds specifically to the variable domain of Ig κ light chain, as a consequence Protein L has the capacity to purifiy κ light containing IgA antibodies.

It should be noted that protein L binding is restricted to specific subclasses of the kappa domain.

As Protein L recognizes κ light chains, protein L can bind to all classes of Ig, in contrast to Protein A and Protein G which interact with the Fc region and bind exclusively to IgG heavy chains.

Protein L does not bind bovine immunoglobulins which are present in the fetal bovine serum (FBS) and thus provides a convenient way to purify κ light chain-containing monoclonal antibodies from culture supernatant.