Isolation of LSK/EPCR⁺ cells using flow cytometric and CFU-C analysis. (A) After mature blood cell lineage predepletion, E12.5 mouse FL cells were gated against viable immature hematopoietic cells. Subsequently, the LSK fraction was determined and was subdivided into EPCR⁺ and EPCR⁻ fractions. Sorted LSK/EPCR⁺ and LSK/EPCR⁻ cells were submitted to CFU-C analysis. LSK/EPCR⁺ cells formed a significantly higher number of colonies at all observation stages (B), as well as a larger variety of colonies (C). Error bars represent SD (n = 3). *P < .05, **P < .01.