CD105 is a 90 kD homodimeric type I integral membrane glycoprotein, also known as endoglin. It is expressed on endothelial cells within endothelial tissue. However, CD105+ cells can also be isolated from human bone marrow. Upon culturing, these CD105+ cells show similar characteristics to plastic-adherent mesenchymal stem cells (MSCs). Cultured CD105+ cells express CD105, CD44, CD29, CD90 and CD106 but do not express CD14, CD34, CD45, or CD31 surface antigens. These cells demonstrate multilineage differential capacity into osteogenic, chondrogenic and adipogenic lineages.

Bone marrow mononuclear cells (MNCs) are separated from whole bone marrow by a density gradient centrifugation protocol. Bone marrow CD105+ cells are positively selected using immunomagnetic anti-CD105 microbeads from the MNC population. Isolated primary cells are characterized by flow cytometry prior to cryopreservation to ensure a highly pure and viable cell population.

Cells were obtained using Institutional Review Board (IRB) approved consent forms and protocols.