Synthesis and application of a poly(ethylene glycol)-antibody affinity ligand for cell separations in aqueous polymer two-phase systems.
The possibility of producing biospecific affinity ligands for separating cells in two polymer aqueous phase systems on the basis of cell surface antigens was investigated. Rabbit anti-human erythrocyte IgG was reacted with cyanuric chloride-activated monomethyl poly(ethylene glycol) (PEG) fractions (molecular weights approximately 200, 1900, and 5000) at various molar ratios of PEG to protein lysine groups. The partition coefficient of the protein in a Dextran/PEG two-phase system increased with increasing degree of modification and increasing PEG molecular weight. There was a concomitant loss in ability to agglutinate human erythrocytes. The ability of the modified IgG to bind to a DEAE-cellulose column was almost eliminated by reaction with the PEG 5000, and was decreased to a lesser extent by PEG 1900. This PEG 1900-modified IgG substantially increased the partition of fresh or fixed human erythrocytes into the PEG-rich phase of a suitable phase system, while having no effect on rabbit cell partition. The partition increase could be inhibited by unmodified anti-human red cell IgG but not by nonspecific unmodified human IgG, demonstrating that the ligand effects were specific for the cell type against which the antibody was raised. A mixture of rabbit and human erythrocytes, which ordinarily have very similar partitions in the phase systems used, could be separated on a countercurrent distribution apparatus using the modified IgG. These results demonstrate the feasibility of producing immunologically specific affinity partition ligands for cell separation.
K A
KA
Sharp
M
M
Yalpani
S J
SJ
Howard
D E
DE
Brooks
D000345:Affinity Labels; D000818:Animals; D000915:Antibody Affinity; D002469:Cell Separation / Q000379:methods*; D003377:Countercurrent Distribution; D004912:Erythrocytes / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G; D011092:Polyethylene Glycols; D011817:Rabbits
D000345:Affinity Labels; D007074:Immunoglobulin G; D011092:Polyethylene Glycols