丁香实验_LOGO
登录
热门搜索
donkey anti-sheep igg (hhuman igg (h无酶无菌水北京厂家[jl43163] 鸡z-dna结合蛋白(zbp)elisa试剂盒goat anti-rat igg (hgoat anti-rabbit igg (h5ml大容量吸头anti-adducin protein  内收蛋白抗体goat anti-mouse igg (h细胞病毒感染
提问
我要登录
|免费注册
点赞
收藏
wx-share
分享

Intracellular pH and pCa Measurement

互联网

579
Recent improvements in confocal technology permit the use of a confocal microscope as an effective tool to both measure concentration and visualize distribution of several ions. Effective discrimination against out-of-focus information in the confocal microscope permits for mapping of ion distribution at the subcellular level (1 ). To generate such a map with any degree of accuracy it is necessary to compensate for inherent cellular inhomogeneities in optical path, probe distribution, etc. To do so ratiometric measurements are usually employed (2 ,3 ). Fluorescence ratiometry takes advantage of a differential spectral sensitivity of a ratio probe to the measured parameter (e.g., ion concentration). Whereas fluorescent properties of the ratio probe at one wavelength are parameter sensitive in one manner, the emission (or excitation) of the probe at a distinct, well-separated wavelength must be either parameter insensitive, inversely sensitive, or exhibit a different sensitivity profile. Emission intensities for the two wavelengths are then divided by each other and thus the resulting ratio becomes normalized for inhomogeneities in probe distribution and concentration and in the system geometry. To obtain meaningful data the ratio values must be calibrated against a standard, which usually is a graded change in the parameter. Modern day confocal microscopy depends on lasers as light sources which causes a severe limitation in number of wavelengths available for fluorochrome excitation. Several H+ -sensitive fluorochromes are excited at wavelengths close to those emitted by standard lasers, however, this is not the case with Ca2+ -sensitive fluorochromes (4 ).
提问
扫一扫
丁香实验小程序二维码
实验小助手
丁香实验公众号二维码
扫码领资料
反馈
TOP
打开小程序