ANALYSIS OF SINGLE FLUORESCENT MOLECULES TRAPPED INSIDE SMALL LIPID VESICLES

缓解改善的依据（ 荧光，（F/F）的电压敏感染料已被测试。 对目前表现出电压敏感性的染料的改进 （F/F最多为10%，这将引起神经科学家的极大兴趣。 Di-8-ANEPPS的双光子作用截面， 光稳定的、相对无细胞毒性的染料相对于 MeOH中的罗丹明B，800-1000 nm。 双光子激发 选择波长以最大化 相对于波长的横截面。 Hela细胞负载有 在K+去极化之前和之后对染料进行成像以定量（F/F 膜电位的巨大变化。 无明显改善 使用双光子激发观察。 进一步调查 使用膜片钳技术， 激发波长正在进行中。

A rationale for improvement of the response (fractional change in fluorescence, (F/F) of a voltage-sensitive dye has been tested. Improvement of current voltage-sensitive dyes which currently show (F/F of 10% at best, would be of great interest to neuroscientists. The two-photon action cross-section of Di-8-ANEPPS, a bright, photostable, relatively non-cytotoxic dye was measured relative to Rhodamine B in MeOH from 800-1000 nm. A two-photon exctiation wavelength was chosen to maximize the magnitude and slope of the cross-section with respect to wavelength. Hela cells were loaded with the dye and imaged before and after K+ depolarization to quantify (F/F for a large change in membrane potential. No conclusive improvement was observed using two-photon excitation. Further investigation of the same molecule using patch-clamp techniques and different excitation wavelengths is underway.