Surface affinity chromatographic separation of blood cells. III. Effect of molecular weight of polyethylene glycol bonded stationary phases on elution behaviour of human blood cells.

The chromatographic behaviour of human peripheral blood cells on four kinds of oxirane-coupled polyethylene glycol (PEG)--Sepharose 6B columns was investigated by using an eluent containing 2% of dextran T40. The retention volumes of lymphocytes, granulocytes and platelets at pH 7.5 have a strong dependence on the average molecular weight of the bonded PEG in the range 400-20,000, increasing with increasing molecular weight. Further, the same tendency for the retention behaviour was also observed at the isoelectric points determined for the four kinds of blood cells by using the cross-partition method. For lymphocytes and granulocytes hydrophobic interactions with the bonded PEG phase were found to be predominant, whereas for erythrocytes and platelets electrostatic interactions were also taken into account.