Spectroscopy Equipment

  • Made by PTI, the instrument is currently equipped with excitation sources at 473, 375, 310 and 280 nm. The instrument can measure fluorescence decays down to 10 picoseconds, and can resolve multiple components by iterative fitting, including convolution with the exciting pulse shape. National Science Foundation (NSF) logoThe T-2B Steady state enhancement module includes a high intensity continuous xenon source, an excitation monochromator, and a multi-mode PMT detector which can selected by turning a mirror. This allows high quality excitation and emission spectra to be obtained. The instrument is useful for FRET experiments, and can perform high quality fluorescence polarization experiments. Funded by NSF MRI.
  • Stopped flow is a kinetics method used to study single turnover and pre-steady-state kinetics of liquid-phase chemical and biochemical reactions on a timescale down to one millisecond. In stopped flow, reactions are initiated by gas or motor driven syringes that drive solutions through a rapidly mixing chamber into a stationary observation cuvette. Our instrument is equipped for absorbance or fluorescence detection, and can be used in two or three syringe configurations. In the latter, a third reactant can be introduced after a programmed delay. Applications include observation of intermediates in enzyme catalysis, ligand binding to proteins (e.g., receptors or enzyme active sites), and kinetics of protein folding.
  • The Electron paramagnetic resonance (EPR) spectrometer is a Bruker EMX running at X band (9.2GHz), equipped with an ER 083 electromagnet capable of reaching fields of 13 kG. Available cryogenics allow studies down to a few degrees above the boiling point of liquid helium, 4.2K. This allows studies of rapidly relaxing metal centers. EPR is a spectroscopic technique that provides information by detecting transitions between electron spin states. It is useful for studying molecules with unpaired electrons, including free radicals and metal centers. Paramagnetic probes (spin labels) and spin trapping reagents have extended its usefulness greatly.