Purity: > 90% by SDS - PAGE Format: Liquid. In Phosphate Buffered Saline (pH 7.4) containing 20% glycerol.. PSG1, also known as Pregnancy-specific beta-1-glycoprotein 1, is a secreted glycoprotein of the human PSG family within the CEA (carcinoembryonic antigen) superfamily. PSGs (Pregnancy-specific glycoproteins) are a complex consisting of carbohydrate and protein. It is the most abundant protein found in the maternal bloodstream during the later stages of pregnancy and is of vital importance in fetal development. The PSG functions primarily as an immune-modulator to protect the growing fetus. Recombinant human PSG1 protein, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.