Fig. 1

An unbiased approach for immunophenotypic identification of functionally distinct hematopoietic progenitors. a In the classical view of hematopoietic hierarchy progenitors are defined using complex nested gating strategies on defined immunophenotypic markers [2,3,4]. b In our approach we labelled a pool of CD34⁺ HSPCs with the currently established panel of markers and live, single events were index-sorted into an optically-clear 384-well. The progenitor potential of each cell was assessed in a custom colony assay suspension culture system, supplemented with cytokines that can support all myeloid lineages. Colonies were allowed to grow for 14 days and growth was monitored by an automated cell imager. Flow-cytometric analysis identified the type of colony which reflects the lineage potential of the sorted cell. The functional potential of the cell that initiated the colony was then mapped back to the composite phenotype of that cell