TWO PHOTON LASER SCANNING FLUORESCENCE CORRELATION SPECTROSCOPY

双光子激光扫描荧光相关光谱

• 批准号: 6349422
• 负责人: DANIEL LARSON
• 金额: $ 3.56万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6349422
• 关键词: bioengineering /biomedical engineering; biomedical equipment development; biomedical resource; genetics; genome; lasers; technology /technique

Confocal imaging and fluorescence correlation spectroscopy (FCS) was applied towards characterization of lipid phase behavior and diffusion measurements in model lipid membranes. Giant unilamellar vesicles (GUVs) of defined lipid composition were first imaged by confocal fluorescence microscopy. Phase separation was visualized by partitioning of fluorescent lipid analogs with different fatty acid chain lengths into the coexisting phases. Cholesterol induces a marked change in the shapes of the phase domains for the binary mixture of DLPC1/DPPC. Characterization of the dynamics by measuring diffusion coefficients by FCS was carried out in liquid disordered (L__, liquid ordered (Lo) and gel phase (L__. The two-phase region for the binary mixture DLPC/DPPC (L_/L_) was identified by dual mode dynamics recognized in the shapes of the FCS autocorrelation curves. For binary mixtures of DLPC/cholesterol and DMPC/cholesterol, a continuous gradual transition of diffusion coefficients from high values (3.9 x 10-8 cm2/s) in the pure phospholipid down to tenfold slower diffusion as cholesterol was increased up to the phase boundary at 67 mol%.

共焦成像和荧光相关光谱 (FCS) 应用于脂质相行为的表征和 模型脂质膜中的扩散测量。 巨单层 首先对具有确定脂质成分的囊泡 (GUV) 进行成像 共焦荧光显微镜。 相分离通过以下方式可视化 荧光脂质类似物与不同脂肪酸的分配 链长分为共存相。 胆固醇会诱发 二元相域形状发生显着变化 DLPC1/DPPC 的混合物。 通过测量表征动力学 FCS 的扩散系数是在无序液体中进行的 (L__，液体有序 (Lo) 和凝胶相 (L__。两相区域 对于二元混合物 DLPC/DPPC (L_/L_) 通过双模式进行识别 FCS 自相关曲线的形状可识别动力学。 对于 DLPC/胆固醇和 DMPC/胆固醇的二元混合物， 扩散系数从高值连续逐渐过渡 纯磷脂中的值 (3.9 x 10-8 cm2/s) 低至十倍 随着胆固醇增加到相边界，扩散速度减慢 为 67 摩尔%。