Systemic PGE₂ treatment increases the HSC-enriched LSK population without inhibiting hematopoietic differentiation or affecting lineage distribution. (A-C) Peripheral blood analysis of mice treated systemically with PGE₂ or vehicle. (A) The total number of white blood cells present in 1 μL blood. (B) %HCT indicates the percentage of blood volume occupied by red blood cells. (C) The number of platelets present in 1 μL blood. Experiment shown is representative of 3 independent experiments. (D) CFU-C assays on bone marrow cells measure more differentiated hematopoietic progenitor cells with the capacity to form colonies in methylcellulose (n = 4/group). (E-F) Flow cytometric strategy used for quantification of LSK cells in the bone marrow of mice treated with either PGE₂ or vehicle. 4,6-Diamidino-2-phenylindole was used as a DNA stain to exclude nonviable cells. (G) Quantification of bone marrow LSKs from vehicle- and PGE₂-treated C57/bl6 mice (2 separate experiments are included). Points represent the fold difference between PGE₂-treated and VEH-treated animals. (H) LSK quantification from FVB/N mice treated daily for 4, 8, 12, and 16 days with vehicle or PGE₂ as indicated in the graph. *P ≤ .05. **P ≤ .01. ***P ≤ .001.