Fig. 2.

Fluorescence responses of SSP4 (5 μM) toward Na₂S₂ or S₈ (25 μM) in (A) different buffers: (1) 50 mM PBS, pH 7.4; (2) 10 mM PBS, pH 7.4; (3) 50 mM Tris buffer, pH 7.4; (4) 50 mM sodium phosphate buffer, pH 7.4; (5) 50 mM potassium phosphate buffer, pH 7.0; (6) 50 mM HEPES (7) Fluorobrite DMEM; (8) Fluorobrite DMEM + 10% FBS; (9) DMEM; (10) DMEM + 10% FBS. (B) different pHs in 50 mM PBS (pH 7.4). CTAB (25 μM) was added to all reactions, and reactions were carried out for 20 min at room temperature. Results are expressed as mean ± SEM (n = 3).