U9B 		Ultraviolet Circular Dichroism
and Time-Resolved Fluorescence
An Outside User Facility at the NSLS UV-Ring

Contact: John C. Sutherland    
  Biology Department, 463
Brookhaven National Laboratory
Upton, NY 11973-5000 		tel: (631) 344-3279
tel: (631) 344-5509
fax: (631) 344-3407
 jcs@bnl.gov

U9B Group: NSLS Beamline U9B
Denise Monteleone
John G. Trunk 		(631) 344-5509
344 3406 / 5509
233 3406 / 5509 		 
dcm@bnl.gov
trunk@bnl.gov

NSLS Beamline U9B is designed for circular dichroism (CD) in the vacuum ultraviolet to about 160 nm using a calcium fluoride photoelastic modulator. Sample absorption spectra are acquired during the same scan [1]. CD of samples in an aqueous environment can be recorded to 162 nm using varaible pathlength sample cells [2]. Sample temperatures can be controlled in the range from -10°C to + 90°C. CD experiments can also be performed at 77°K or < 20°C.

Excellent CD spectra to 130 nm have been recorded using Beamline U11, and this limit has been extended to ~110 nm using a LiF modulator.

Fluorescence (excitation spectra, emission spectra, and decay histograms) are recorded by single-photon counting techniques using either the vacuum spectrometer (also used for CD) or a sparate non-vacuum spectrometer. Temporal resolution is about 100 ps [3]. Samples can be in cuvettes, or isolated in matrices of nitrogen or argon at cryogenic temperatures [4]. A recently developed system, the Fluorescence Omnilyzer, permits simultaneous recording of the temporal decay profiles of the entire emission spectrum [5], and its polarization anisotropy [6].

Both spectrometers are operated by an Intel Pentium 200 PC running NT 4.0 with archival data storage on a Redhat Linux server.

Denise Monteleone and
John Trunk working at
beamline U9B.

References:
  1. Sutherland J.C., Desmond, E.J. and Takacs P.Z.,
    Versatile spectrometer for experiments using synchrotron radiation at wavelengths greater than 100 nm
    Nucl. Instr. Meth. 172, 195-199 (1980). Abstract
  2. Gray, D.M., Lang, D., Kuner, E., Vaughan, M. and Sutherland, J.C.,
    Thin quartz cell suitable for vacuum ultraviolet absorption and circular dichroism measurements.
    Anal. Biochem. 136, 247-250 (1984). Abstract
  3. Polewski K., Kramer S.L., Kolber Z.S., Trunk J.G., Monteleone D.C. and Sutherland J.C.,
    Time resolved fluorescence using synchrotron radiation excitation: a powered fourth harmonic cavity improves pulse stability.
    Rev. Sci. Instr. 65, 2562-2567 (1994). Abstract
  4. Polewski K., Zinger D., Trunk J., Monteleone D.C. and Sutherland J.C.,
    Fluorescence of matrix isolated guanine and 7-methylguanine.
    J. Photochem. Photobiol. B, 24, 169-177 (1994). Medline Abstract
  5. Kelly, L.A., Trunk, J.G., Polewski, K. and Sutherland, J.C.,
    Simultaneous resolution of spectral and temporal properites of UV and visible fluorescence using single-photon counting with a position-sensitive detector.
    Rev. Sci. Instr. 66, 1496-1498 (1995). Abstract
  6. Kelly, L.A., Trunk, J.G. and Sutherland, J.C.,
    Time resolved fluorescence polarization measurements for entire emission spectra with a resistive-anode, single-photon-counting detector: the Fluorescence Omnilyzer.
    Rev. Sci. Instr. 68, 2279-2286 (1997). Abstract
Beamlines Parameters U9B U11
Application CD, Fluorescence CD, Fluorescence
Spectrometer Type Czerny-Turner / vacuum Wadsworth / vacuum
Wavelength Range 160-600 nm 120-330 nm
Dispersion 1.67 nm/mm 0.32 nm/mm
Image Size at Sample 2 mm diameter 2 mm diameter
Total Angular Acceptance 37H x 10V mradians 55H x 10V mradians

Updated 31 Dec 2003 Security Notice   Webteam   Site Map   Biology Home   BNL Home Page