CD34, also known as hematopoietic progenitor cell antigen CD34 isoform b, is a member of a family of single-pass transmembrane sialomucin proteins. It is adhesion molecule with a role in early hematopoiesis by mediating the attachment of stem cells to the bone marrow extracellular matrix or directly to stromal cells. This protein could act as a scaffold for the attachment of lineage specific glycans, allowing stem cells to bind to lectins expressed by stromal cells or other marrow components. Recombinant human CD34, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.