Effect of LPA on histochemical characteristics of hMCs. (A-C) Toluidine blue staining and (D-F) immunocytochemistry for tryptase of representative hMCs developed in the presence of SCF, IL-6, and IL-10 in serum-free medium (A, D) without and (B, E) with 5.0 μm LPA, and (C, F) under standard serum-supplemented conditions. All cultures were 3 weeks old at the time of analysis. Data are from 1 of 2 representative experiments. Images depicted are 400 × magnifications.