Morphology of Mac1⁺ granular cells. Single cell suspensions of spleen cells from week-3 chimeras and control host-type mice were studied on HE-colored cytospin preparations. One example is shown from a week-3 chimera (A) and a control host-type mouse (B). Mac1⁺ (C) and Mac1- (D) populations were separately studied following MACS separation on the basis of Mac1 expression. One representative example is shown of 12 week-3 chimeras, 6 control host-type mice, and 3 Mac1⁺ and 3 Mac1- cell populations. Original magnification, × 700.