Enrichment of Committed Stem Cells (CFU-C) from Human Peripheral Blood

Summary

The residues obtained from single-donor plateletphereses are a reproducible and convenient source of CFU-C as detected by a double-layer agar culture technique. Enrichment of CFU-C is achieved by sequential sedimentation on LSM, macrophage depletion by adherence to plastic, and isopycnic centrifugation on BSA gradients. The final preparation from a single-donor contains approximately 3 × 10⁸ cells, sufficient for 150 quadruplicate cultures. Enrichment of CFU-C was about sixfold and the yield of CFU-C was 76%. Cells from the macrophage-depletion step were suspended in 10% dimethyl sulfoxide, frozen, and stored at —70°. After thawing at 37°, CFU-C were enriched by centrifugation on BSA. Frozen cells retained full CFU-C activity for at least 4 weeks.