Table 4.

Purified basophils generate mast cells in vitro

Well no.	% cells positive with α–mMCP-8 after culture	% mast cells after culture
1	100	8
2	9	20
3	100	35
4	100	17
5	99	100
6	100	15
7	34	4
8	19	2
9	95	23
10	89	88
11	90	12
12	96	32

Each well contained 5 × 10³ CD49b⁺, Kit^–, FCγR⁺, IgE⁺, and Gr1⁻ cells, 100% of which positively stained with anti–mMCP-8. The cells were then stimulated for 2 wk in liquid culture by SCF+IL-3. After this incubation, the mean cell counts in the wells were 3.5 ± 2.3 × 10³.