A New Methylene Blue Technic for Permanent Preparations

Abstract

1. Tissues stained intra vitam with methylene blue are fixed in a 10% ammonium molybdate solution in physiological saline (or sea water if the tissue is from a marine animal). Fixation time is kept to a minimum. Washing also is reduced to a minimum. 2. Excess fluids are removed from tissues by blotting with a paper or cloth towel before they are put into the succeeding solution. Tissues are taken from the wash water, blotted and placed in a mixture of equal parts of absolute ethyl alcohol and n-butyl alcohol for 30 minutes. They are then blotted and transferred to n-butyl alcohol for 30 minutes. After blotting they are placed in a mixture of one part methyl salicylate and four parts xylene until cleared. Tissues may be mounted whole or prepared for sectioning by embedding in paraffin in the usual way. 3. Tissues fixed, washed, dehydrated and cleared as described retain nearly all of the stain; the time required is greatly reduced; there is no need to chill the dehydrating solutions; cell distortion is much reduced.