Center for Fluorescence Spectroscopy-Advanced studies of fluorescence dynamics, lifetime imaging, clinical sensing, two-photon excitation and light quenching

摘要

The Center for Fluorescence Spectroscopy (CFS) is a multi-user facility providing state-of-the-art time-resolved fluorescence instrumentation and software for scientists, whose research can be enhanced by such experimental data. The CFS is a national center, supported by the National Center for Research Resources Division of the National Institutes of Health, and in part by the National Science Foundation. Both time-domain (TD) and frequency-domain (FD) measurements (10 MHz to 10 GHz) are available, with a wide range of excitation and emission wavelengths (UV to NIR). The excitation sources for both domains are cavity dumped and frequency-doubled ps dye lasers. Time-correlated single photon counting is accomplished with a 6μ red-sensitive microchannel plate (MCP)-PMT, to provide an instrument response near 60 ps. Frequency-domain measurements are possible up to 10 GHz using the Center's frequency-domain instrument, which has 6μ UV and red-sensitive MCP-PMT. Available excitation wavelengths range from 280 to 850 nm. High resolution fluorescence intensity or anisotropy decays can be obtained with the assistance of CFS personnel. The data can be used to recover distances and site-to-site diffusion in protein, interactions between macromolecules, accessibility of fluorophores to quenchers, and the dynamic properties of proteins, membranes and nucleic acids. Current software provides for analysis of multi-exponential intensity and anisotropy decays, lifetime distribution, distance distributions for independent observation of fluorescence donors and acceptors, transient effects in collisional quenching, phase-modulation spectra and time-resolved emission spectra. Most programs provide for global analysis of multiple data sets obtained under similar experimental conditions. Data can be analyzed on-site by connection with the CFS computers through the Internet. During six years of operation we have established scientific collaborations with over 30 academic and industrial groups in the United States. These collaborations have resulted in 63 scientific papers.