A procedure for dehydrating methylene blue stained protozoan smears, which should be applicable to the dehydration of tissues stained intra vitam with methylene blue: Wash with distilled water, place in tertiary butyl alcohol for 1-2 min., then in 3 or more changes of tertiary butyl alcohol for 15 min. to an hour each, and mount directly in balsam or pass through 2 changes of xylene before mounting.