POLARIZATION BASED SENSING

我们描述了使用 长波长钙指示器，钙绿、橙色和深红色。 使用频域测量了这些探头的寿命 方法，并发现从50%增加到几倍的响应 到钙质。钙离子浓度的二维图像 使用一种新的荧光寿命成像设备获得 (电影)。我们还描述了纠正 增益调制图像的位置相关频率响应 胶片设备中使用的增强器。重要的是，薄膜方法 不要求探头显示激励或 发射光谱。使用薄膜方法，钙成像是可能的。 使用显示寿命随钙变化的探针。 因此，利用激发波长进行钙成像是可能的 范围从488 nm到长达620 nm，其中自发荧光和/或 光化学损害很小。这些探头也适用于 基于寿命流动法的单细胞钙测量 细胞学。

We describe imaging of calcium concentrations using the long-wavelength Ca2+ indicators, Calcium Green, Orange, and Crimson. The lifetimes of these probes were measured using the frequency-domain method and were found to increase from 50% to several fold in response to calcium. The two-dimensional images of the calcium concentration were obtained using a new apparatus for fluorescence lifetime imaging (FLIM). We also describe procedures to correct for the position-dependent frequency response of the gain-modulated image intensifier used in the FLIM apparatus. Importantly, the FLIM method does not require the probe to display shifts in the excitation or emission spectra. Using the FLIM method, calcium imaging is possible using probes which display changes in lifetime in response to calcium. Consequently, calcium imaging is possible with excitation wavelengths ranging from 488 to as long as 620 nm, where autofluorescence and/or photochemical damage is minimal. These probes are also suitable for calcium measurements of single cells using lifetime-based flow cytometry.