Effect of BAH-1 MoAb on murine immature megakaryocytes by using a single megakaryocyte growth assay. Single megakaryocytes were scored as the number of acetylcholinesterase-positive cells per fractionated 5 × 10⁴ bone marrow cell cultures. Results are the means ± SEM from triplicate cultures from three experiments. *Results were significantly different (P < .01) from FCS control.