Lymphoblastoid cell-produced immunoglobulins: preparative purification from culture medium by hydroxylapatite...

Hydroxylapatite (HA) is a chromatography matrix capable of separating nucleic acid as well as protein species. HA adsorbs biomolecules as a function of the extent and distribution of their surface charge. HA has been evaluated for its ability to differentially retain immunoglobulin molecules, which are planar relative to the generally globular serum proteins, particularly albumin, contained in tissue culture medium. HA chromatography provides a single-step method to purify and concentrate immunoglobulin proteins secreted by lymphoblastoid cells into culture medium from the vast excess of serum proteins used to supplement the medium. A human lambda light-chain protein was recovered in 5% of the applied volume of medium, and was separated from 95% of the total protein. More than 75% of a hybridoma-produced complete immunoglobulin was recovered essentially free of serum protein contamination. HA appears to provide a valuable alternative chromatographic medium for the purification of immunoglobulin proteins secreted by lymphoblastoid cells.