THY1, as known as Thy-1 membrane glycoprotein, is a cell membrane protein which contains 1lg-like V-type (immunoglobulin-like) domain. This protein is a member of the immunoglobulin superfamily of adhesion molecules with constitutive expression on fibroblast cells. It can be used as a marker for a variety of stem cells and for the axonal processes of mature neurons. Also, this protein led to some of the initial biochemical description and characterization of a vertebrate glycophosphatidylinositol (GPI) anchor and also the first demonstration of tissue specific differential glycosylation. Recombinant human THY1, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.