Purity of the CD34⁺Lin⁻DR⁻ population by double sorting. Shown are the representative data from one double-sorting experiment. (Left) Initial sort of the CD34-enriched population for CD34-SA670 and the FITC lymphoid cocktail (HLA-DR for the initial sort not shown). Cells were double sorted positive for surface CD34, lymphoid lineage negative, and HLA-DR negative/low. Reanalysis of all events (no exclusion by gating) after the second round of sorting is shown for CD34 and the lymphoid cocktail (middle) and for CD34 and HLA-DR (right). In each experiment, greater than 99.8% of events were within the CD34⁺Lin⁻(based on isotype controls) and CD34⁺DR⁻sort windows as shown. The 0.2% double-negative events were back gated and likely represent debris based on forward and side scatter analysis showing a majority of events (10 of 15 events for the example shown) were to the left of the lymphoid window (data not shown).