title: Near-field microscopy and fluorescence spectroscopy: application to chromosomes labelled with different fluorophores.
abstract: We have coupled a spectrophotometer with a scanning near-field optical microscope to obtain, with a single scan, simultaneously scanning near-field optical microscope fluorescence images at different wavelengths as well as topography and transmission images. Extraction of the fluorescence spectra enabled us to decompose the different wavelengths of the fluorescence signals which normally overlap. We thus obtained images of the different fluorescence emissions of acridine orange bound to single or double stranded nucleic acids in human metaphase chromosomes before and after DNAse I or RNAse A treatment. The analysis of these images allowed us to visualize some specific chromatin areas where RNA is associated with DNA showing that such a technique could be used to identify multiple components within a cell.
authors.affiliation: Université Montpellier 2, IES UMR5507, Place E. Bataillon, 34095 Montpellier cedex5, France.
authors.forename: L
authors.initials: L
authors.lastname: Mahieu-Williame
authors.forename: P
authors.initials: P
authors.lastname: Falgayrettes
authors.forename: L
authors.initials: L
authors.lastname: Nativel
authors.forename: P
authors.initials: P
authors.lastname: Gall-Borrut
authors.forename: L
authors.initials: L
authors.lastname: Costa
authors.forename: T
authors.initials: T
authors.lastname: Salehzada
authors.forename: C
authors.initials: C
authors.lastname: Bisbal
mesh_terms: D002843:Chromatin / Q000648:ultrastructure; D002877:Chromosomes, Human / Q000648:ultrastructure*; D005456:Fluorescent Dyes / Q000494:pharmacology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008853:Microscopy / Q000379:methods*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013194:Staining and Labeling / Q000379:methods
chemical_list: D002843:Chromatin; D005456:Fluorescent Dyes