A. Mathey et Pb. Lukins, Spatial distribution of perylenequinones in lichens and extended quinones in quincyte using confocal fluorescence microscopy, MICRON, 32(2), 2001, pp. 107-113
The application of confocal fluorescence microscopy and microspectrofluorim
etry to the characterization of the distribution of organic compounds in bu
lk lichens and mineral structures is demonstrated. Perylenequinones and ext
ended quinones were chosen as both model compounds and as the naturally occ
urring fluorophores. These molecules occur, respectively, in corticolous mi
crolichens and in a pink-colored mineral called quincyte. The structures of
quincyte and of the lichens Cryptothelium rhodotitton and Graphis hematite
s are described, and the possibilities of energy dissipation and photoprote
ction mechanisms in these lichens are discussed. This study also illustrate
s how, for a wide range of specimens, naturally occurring quinone fluoropho
res in the specimen can be exploited directly to yield chemical and structu
ral information without using fluorescent labelling. These intrinsic quinon
oid compounds have molecular fluorescence yields and laser damage threshold
s comparable or superior to common microscopy dyes, and can therefore be us
ed to obtain high-contrast 3D fluorescence imaging without the complication
s introduced by dye labelling. (C) 2000 Elsevier Science Ltd. All rights re
served.