We will be determining chlorophyll and other pigment concentrations from
moss 'stem' tips using DMSO (dimethyl sulfoxide) and I have equations
for determing chlorophyll a and b from spectrophotometric reading from
Barnes et al. (1992). Also, Ronen and Galun (1984) introduce the
"phaeophytinization quotient", or O.D.435/O.D.415, as an indication of how
much chlorophyll has been changed to phaeophytin.
A couple questions: Does anyone know of an equation, from literature or
otherwise, for direct measure of phaeophytin? Are there any equations for
chlorophyll concentrations that are more accurate, up-to-date? And, does
most degradation from chlorophyll to phaeophytin, as found in DMSO
extracts, occur in DMSO, or in the plant before extraction? I suppose it
is possible for both to occur, but I am curious whichi is found to be more
Please email directly, as newsgroup post propagation is often slow.
Barnes, J. D., L Balaguer, E. Manrique, S. Elvira, and A. W. Davison.
1992. A reappraisal of the use of DMSO for the extraction and
determination of chlorophylls a and b in lichens and higher
plants. Environmental and Experimental Botany 32: 85-100.
Ronen, R., and M Galun. 1984. Pigment extraction from lichens with
dimethyl sulfoxide (DMSO) and estimation of chlorophyll
degradation. Environmental and Experimental Botany 24: 239-245.
Bill Boelema | Graduate Student, Biological Sciences
wjboelem at mtu.edu | Michigan Technological University