Distribution of Mineral Ash in Striated Muscle Cells,

Abstract

This report is a brief account of one phase of a study of the distribution of inorganic salts, in various tissues and cell types, as revealed by the technique of microincineration. The method of incinerating thin sections of tissue without disturbing the topography of the mineral components was suggested by Liesegang, 1 but its advantages were never realized until the researches of Policard. 2 Until recently the technique has been largely a gross histologic one because of inherent difficulties in making observations with the higher powers of the microscope. However, it was discovered by the writer 3 , 4 , 5 that the use of the dark field condenser of Zeiss removed to a large extent these difficulties and rendered it possible to follow through even the changes of the fixed minerals of the nucleus during mitosis.

It is necessary to use a fixative which neither removes nor increases the inorganic elements of the tissue. Absolute alcohol is best adapted for this purpose, but gives poor fixation even under the most favorable circumstances. It was found after some experimentation that a mixture of 9 parts of absolute alcohol to 1 part of neutral formalin (Will Corporation) gives rather good cytologic detail and yet, for all practical purposes, does not change the original inorganic constitution of the tissue. After fixation for 24 hours the tissue is passed through several changes of absolute alcohol to complete the dehydration. The specimens are then cleared in xylol, embedded in paraffin and cut serially at 4 microns. Alternate sections are mounted according to the usual technique and stained with haematoxylin and eosin. The intervening sections of the series are mounted on glass slides with liquid petrolatum as a medium in which to spread the tissue.