ESR Spin-labeling method of determining membrane fluidity in biological materials. Tissue culture cells, cardiac mtiochondria, erythrocytes and epidermal cells.

Abstract

The spin-labeling technique with electron spin resonance (ESR) was introduced to determine membrane fluidity in plasma membranes. Three kinds of doxylstearic acid were used as spin labeling agents. The experimental conditions of ESR measurement, such as spin probe concentration, number of cells, decay of ESR specturum, incubation time, ESR cavity temperature, and microwave power, were discussed with the aim of obtaining reproducible ESR spectra. As biological material, B-16 melanoma cells, Ehrlich ascites tumor cells, epidermal cells, erythrocytes and cardiac mitochondria were used.