Table 1.

Bone marrow subpopulations generate mast cells

Marrow subpopulation	No. of cells per well	% mast cell-containing wells
Lineage+	10,000	8
Lineage–	10,000	100
Lin– Kit+ Sca1–	500	100
Lin– Kit– Sca1–	500	0
Lin– Kit– Sca1+	500	17
Lin– Kit+ Sca1+	500	100

A total of 12 replicate wells in two separate experiments were used per fraction. In some cases, negative wells contained no living cells.