Human multipotent mesenchymal stromal cells (MSCs), also referred to as mesenchymal stem cells, are a rare population of adult stem cells that can be isolated from a variety of tissues.  MSCs that have been isolated from bone marrow and subsequently cultured can differentiate to a variety of cell types, most notably adipocytes, osteocytes and chondrocytes.  MSCs also have immunomodulatory effects in vivo and in vitro.  In 2006, the International Society for Cellular Therapy (ISCT) proposed a cell surface marker panel for the minimal identification of human MSCs derived from bone marrow.  Under this recommendation MSCs should be positive for CD73, CD90, and CD105, but be negative for CD34, CD45, CD11b or CD14, CD19 or CD79α, and HLA-DR.  MSCs are also known to express numerous cell surface markers such as CD44, CD29, CD200, CD166, CD146 and CD271.  In this kit we include the panel that was proposed by the ISCT.  In addition, we designed this kit to be modular so that additional markers could be "dropped-in".  Specifically, the MSC positive cocktail (FITC CD90, PerCP-Cy?5.5 CD105 and APC CD73) leaves the PE channel open to use in combination with the supplied negative MSC cocktail (PE CD45, PE CD34, PE CD11b, PE CD19 and PE HLA-DR), the included PE CD44 antibody conjugate, or a variety of other commercially available PE antibody conjugates.  Multi color analysis minimizes cell numbers required for an assay and antibody cocktails facilitate a streamlined staining protocol to analyze multiple samples.  Individual positive markers are included for compensation set-up.