Process for fractionating polyethylene glycol (PEG)-protein adducts and an adduct for PEG and granulocyte-macrophage colony stimulating factor

摘要

The invention relates to fractionating a mixture of polyethylene glycol (PEG)-protein adducts having different degrees of PEG substitution by partitioning the PEG-protein adducts in a PEG-containing aqueous biphasic system according to the degree of PEG substitution. A new PEG-gm-CSF obtained by the process is useful in pharmaceutical compositions for use in therapeutic or diagnostic methods.