Determination of Mass of Nerve-cell Components

The method for determination of mass in biological material described by Engström & Lindström (1950) is founded on the fact that the absorption of X-radiation at 8–10 Å is proportional to the mass of the biological substance. In elaborating this method for quantitative analysis of nerve-cells and their components (Brattgård & Hydén, 1952) we found it important to consider the following sources of error: 1. The reference system. 2. The photographic process and the photometry. 3. The treatment of the material. 1. The reference system. The error in the reference system was investigated and a new method was elaborated at the Histological Department in Göteborg for the production of the thin cellulose foils which constitute the reference system (Bråttgard & Hallén, 1952; Bråttgard & Hydén, 1952; Hallén, 1953). We found, however, that this gravimetric method for the control of the mass per unit surface of the reference system involved too great an error.