POGLUT1, also known as protein O-glucosyltransferase 1, is a homologue of Rumi from Drosophila, an endoplasmic reticulum (ER)-retaining glucosyltransferase that adds glucose to serine residues within the consensus sequence of C1-X-S-X-P-C2 in Notch EGF repeats, thereby regulating cell-fate decisions. Recombinant human POGLUT1, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.