William Smith raised an important point which others are probably
better qualified to address than myself.
Dr Smith asked 'Are all FITCs the same ?' and then quoted diffences
in observed spectral overlap when using FITC conjugated to different
molecules viz antibodies, dextran ...
In our paper: Flow cytometric quantification of electroporation
mediated uptake of macromolecules into plant protoplasts, Protoplasma
186:50-56, 1995, we were able to distinguish between FITC and
dextran-conjugated FITC based on yellow/orange discrimination.
The spectral properties of fluorescein are dependent upon the miroenvironment,
principally pH. It is therefore not surprising, in a simplistic way, that different
FITC-labelled probes have characteristic properties.
Perhaps some of our more enlightened colleagues could explain Dr
Smith's observations.
Yours sincerely,
Nigel Blackhall,
University of Nottingham, UK