Prss28, also known as serine protease 28, belongs to the S1 serine proteinase family with a conserved Histidine-Aspartic Acid-Serine catalytic triad. It exhibits mixed substrate specificity that silences signaling via proteinase-activated receptors. It is involved with embryo hatching and its activity is important for successful implantation. Recombinant mouse Prss28, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.