A Method for the Analysis of Tissues*

The object of tissue analysis is to secure an accurate representation of the condition of the tissue in its normal state. This can be accomplished only by first maintaining conditions which prevent further changes during the final preparation of the tissue. In the procedures now in general use the tissue is rapidly frozen in liquid air (1) or a CO2 snow-ethyl chloride mixture. It is then either thinly sliced while still frozen and immersed in trichloroacetic acid (2) or ground in a cooled mortar containing sand and various precipitants (1, 3). We have found these methods to be not only tedious but clumsy, particularly when multiple samples are being prepared. Furthermore, losses from spattering and evapo.. ration may occur in the use of the open mortar for the grinding of the tissue. In the procedure to be described, the authors have attempted to simplify the technique in order to minimize the possibility of errors in the sampling and preparation of the tissue and to facilitate the handling of multiple specimens. Tissue samples of from 1 to 10 gm. may be treated with equal facility.