Alcohol-XyleneVersusDioxane in the Shrinkage of Tissue

Abstract

A direct measure of tissue volume changes using fluid displacement was employed to compare the effects of the ethyl alcohol-xylene with the dioxane method of tissue processing. Pieces of mouse kidney, spleen, testis and liver were compared after fixation in 10% neutral formalin and during clearing, dehydration and paraffin infiltration. It was found that 24 hr after fixation there was a 25% increase in volume. There was a progressive shrinkage during dehydration and clearing with dioxane to the volume of the tissue before fixation and a subsequent shrinkage of about 20% during paraffin infiltration. With the ethyl alcoholxylene method, tissue volumes returned to initial levels during alcohol dehydration, and progressively shrank with xylene treatment and paraffin infiltration. The final degree of shrinkage was about the same with both methods. This was confirmed from microscopic analysis of tissue components. It is concluded that one cannot use gross tissue shrinkage as the only criterion for selecting one method of tissue processing over another.