ST6GAL1, also known as beta-galactoside alpha-2,6-sialyltransferase 1, is a type II membrane protein localized in the trans-Golgi network and catalyzes 2,6-sialylation of Gal beta 1,4-GlcNAc structures on N-glycans. It is highly expressed in the liver and also expressed in most other tissues to some extent. Its deficiency causes abnormalities in B cell immunoreactivity. Recombinant human ST6GAL1, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.