Chlorophyll can be removed (after GUS staining) by incubation of tissue in
successively higher concentrations of EtOH (e.g. 30%, 50% 70%) for perhaps 1 or
2 hr per incubation, or overnight if more convenient. To fully bleach the
tissue, several incubations in 70% EtOH may be necessary, depending on volume
and tissue mass used. The GUS staining appears to be stable to this treatment
and stained tissue can be preserved in 70% EtOH for many months.
Biochem Dept, Stanford