title: Fluorescence polarization standard for near infrared spectroscopy and microscopy.
abstract: We present studies of polarized absorption [linear dichroism (LD)] and fluorescence polarization of the styryl derivative (LDS 798) embedded in oriented poly(vinyl alcohol) (PVA) films. These films were oriented by progressive stretching up to eight folds. Both vertical and horizontal components of absorptions and fluorescence were measured and dichroic ratios were determined for different film stretching ratios. The dichroic ratio and fluorescence anisotropy values were analyzed as a function of PVA film stretching ratio by fitting according to the previously developed theory. For maximum stretching ratios, exceptionally high anisotropy (approximately 0.8) and polarization (approximately 0.9) values have been measured. The stretched films have high polarization values also for isotropic excitation in a wide spectral range (500-700 nm). Such films can be conveniently used as high polarization standards and we envision they will also have applications in near infrared (NIR) imaging microscopy, where they can be used for correcting an instrumental factor in polarization measurements.
authors.affiliation: Center for Commercialization of Fluorescence Technologies (CCFT), Department of Molecular Biology & Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107, USA. rluchows@hsc.unt.edu
authors.forename: Rafal
authors.initials: R
authors.lastname: Luchowski
authors.forename: Pabak
authors.initials: P
authors.lastname: Sarkar
authors.forename: Shashank
authors.initials: S
authors.lastname: Bharill
authors.forename: Gabor
authors.initials: G
authors.lastname: Laczko
authors.forename: Julian
authors.initials: J
authors.lastname: Borejdo
authors.forename: Zygmunt
authors.initials: Z
authors.lastname: Gryczynski
authors.forename: Ignacy
authors.initials: I
authors.lastname: Gryczynski
mesh_terms: D008567:Membranes, Artificial; D008856:Microscopy, Fluorescence / Q000592:standards*; D008859:Microscopy, Polarization / Q000592:standards*; D011142:Polyvinyl Alcohol / Q000737:chemistry* / Q000592:standards; D012016:Reference Values; D012031:Refractometry / Q000592:standards*; D019265:Spectroscopy, Near-Infrared / Q000592:standards*; D014481:United States
chemical_list: D008567:Membranes, Artificial; D011142:Polyvinyl Alcohol