Cell dose and engraftment in minimally irradiated recipients. Male marrow cells in doses of 2, 10, or 40 million cells were infused into female recipients treated with 0, 100, and 700 cGy, and the percentage of engraftment was determined after 2 months. The results show that donor cell readout in hosts after transplant is related to cell dose and irradiation dose to recipient animals. Cell doses as low as 10 million may yield up to 40% in the readout in animals receiving 100 cGy. Experimental points include 5 mice per cell level; where standard errors are not apparent, they fall within the symbol.