中文摘要：

荧光相关光谱（fluorescence correlation spectroscopy,FCS）是一种通过监测荧光涨落从而获得单分子水平的分子扩散行为信息的技术.FCS高灵敏度的优点使得它已发展成为一种可以在活体外与活体内检测分子浓度、扩散系数、结合和解离常数等参数的有力工具.荧光互相关光谱（fluorescence cross-correlation spectroscopy,FCCS）是FCS技术的进一步发展,其大大扩展了FCS技术的应用范围.本文介绍了FCS及其衍生技术的原理及其在生物化学领域的应用.

英文摘要：

Fluorescence correlation spectroscopy （FCS） is a technology to measure the fluorescence fluctuations of a molecular system, which are correlated to the evolution of the system. Owing to the high sensitivity of FCS, it has been developed to be a powerful tool to measure local concentration, diffusion coefficients, association and dissociation con- stants, and other useful quantities, either in simple artificial models or directly in living cells. Fluorescence cross-corre- lation spectroscopy （FCCS） has expanded the utility to encompass a wide range of promising applications. This paper in- troduces the theory of FCS and its application in biochemistry.