title: Fluorescence polarization: measurements with a photon-counting photometer.
abstract: A T-format, photon-counting polarization photometer was constructed to facilitate precise polarization measurements at low signal-to-noise ratios. The instrument optics and electronics are described. Several examples of the instrument's performance are given, including measurements on picomolar fluorescein solutions at low excitation resolution and the excitation polarization spectrum of indole (2 x 10(-4)M) at a resolution of 5 A.
authors.affiliation: Biochemistry Department, University of Illinois, Urbana, IL 61801, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Jameson
authors.forename: G
authors.initials: G
authors.lastname: Weber
authors.forename: R D
authors.initials: RD
authors.lastname: Spencer
authors.forename: G
authors.initials: G
authors.lastname: Mitchell
mesh_terms: D000669:Amplifiers, Electronic; D004581:Electronics / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D010783:Photometry / Q000295:instrumentation*; D017785:Photons; D012031:Refractometry / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*