PT - JOURNAL ARTICLE AU - Alborz Karimzadeh AU - Vanessa Scarfone AU - Connie Chao AU - Karin Grathwohl AU - John W. Fathman AU - David Fruman AU - Thomas Serwold AU - Matthew A. Inlay TI - The CD11a and EPCR marker combination simplifies and improves the purification of mouse hematopoietic stem cells AID - 10.1101/219063 DP - 2017 Jan 01 TA - bioRxiv PG - 219063 4099 - http://biorxiv.org/content/early/2017/11/13/219063.short 4100 - http://biorxiv.org/content/early/2017/11/13/219063.full AB - Hematopoietic stem cells (HSCs) are the self-renewing multipotent progenitors to all blood cell types. Identification and isolation of HSCs for study has depended on the expression of combinations of surface markers on HSCs that reliably distinguish it from other cell types. However, the increasing number of markers required to isolate HSCs has made it tedious, expensive, and difficult for newcomers, suggesting the need for a simpler panel of HSC markers. We previously showed that phenotypic HSCs could be separated based on expression of CD11a, and that only the CD11a negative fraction contained true HSCs. Here, we show that CD11a and another HSC marker, EPCR, can be used to effectively identify and purify HSCs. We introduce a new two-color HSC sorting method that can highly enrich for HSCs with efficiencies comparable to the gold standard combination of CD150 and CD48. Our results demonstrate that adding CD11a and EPCR to the HSC biologist’s toolkit improves the purity of and simplifies isolation of HSCs.Significance Statement The study of hematopoietic stem cells (HSCs) and their purification for transplantation requires a panel of surface markers that can be used to distinguish HSCs from other cell types. The number of markers necessary to identify HSCs continues to grow, making it increasingly difficult to identify HSCs by flow cytometry. In this study, we identified a combination of two surface markers, CD11a and EPCR, to enrich for HSCs in the mouse bone marrow without the need for additional markers. This simplified panel could aid HSC research by reducing the number of markers necessary to identify and isolate HSCs.