UMBC
Location
Mathematics/Psychology : 401
Date & Time
November 11, 2019, 11:00 am – 12:00 pm
Description
Title: Analysis and Simulation of Fluorescence Correlation Spectroscopy
Abstract: Fluorescence Correlation Spectroscopy (FCS) is a tool to determine the diffusivity of fluorescently labeled molecules in the solution by measuring the fluctuation of fluorescence intensity. We provide a mathematical derivation to illustrate how the correlation of the intensity signal reveals the diffusivity. In FCS experiment, particles are doing reflected Brownian motion in a container and as they diffuse into and out of the very small confocal volume illuminated by a laser beam, the fluorescence intensity fluctuates. The fluorescence intensity could be modeled as a stochastic process governed by the motion of particles. The autocorrelation of the intensity has an analytical form as a function of time lag and diffusion coefficient, so the diffusion coefficient could be fitted from the experimentally measured autocorrelation function. To quantify the uncertainty, we derive a formula for the variance of the autocorrelation function in integral form and we find a closed-form upper bound. Monte Carlo simulations will be presented to compare with the theory.
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