Title
Orientation of Carotenoid Molecules in the Eyespot of Alga: In Situ Polarized Resonance Raman Spectroscopy
Author
YOSHIKO KUBO, TERUKI IKEDA, SHI-YUAN YANG, MASAMICHI TSUBOI
Year
2000
Journal
Applied Spectroscopy
Abstract
Raman spectra of single cells of Euglena and Chlamydomonas have
been examined with 514.5 nm excitation at various points within
the cells. At every point, two strong bands, which are assignable to
carotenoid, appeared at 1530 and 1159 cm2 1. By the use of a Raman
mapping system, the Raman intensity at 1530 cm2 1 has been plotted
against the (x,y) coordinate representing a location within the cell.
It has been shown that, for both algae examined, the eyespot has a
prominently high carotenoid content, and a small amount of carotenoid
is uniformly distributed among the chloroplast. The spatial
resolution of the mapping system has been shown to be higher than
1 m m, and the Chlamydomonas eyespot has an elongated shape of
1 m m 3 2 m m. By use of a polarizer, the carotenoid chains in the
Chlamydomonas eyespot have been found to be aligned along its
long axis, which is parallel to the body axis.
Instrument
NRS-2100
Keywords
Raman imagung microscopy,Polarized Raman spectroscopy, In situ mapping; Single cell; Chlamydomonas; Euglena