Molecular profiling of hematopoietic stem cells.

Gene expression profiling using microarrays is a powerful method for studying the biology of hematopoietic stem cells (HSCs). Here, we present methods for activating HSCs with the chemotherapeutic drug 5-Fluorouracil, isolating HSCs from whole bone marrow, and performing microarray analysis. We also discuss quality control criteria for identifying good arrays and bioinformatics strategies for analyzing them. Using these methods, we have characterized the gene expression signatures of HSC quiescence and proliferation and have constructed a molecular model of HSC activation and self-renewal.