Functional selection of HSCs. (A) RFP⁺ endosteal LSK were transplanted into 1 nonablated recipient. After 5 hours, LSK homed to endosteal BM were reisolated and transplanted into ablated secondary recipients in a limiting dilution assay. (B) Limiting dilution analysis of 2 experiments. Each symbol represents a group of mice transplanted with 3, 10, 30, or 100 cells.