FREEZE-ETCHING AND STRUCTURE OF BIOLOGICAL MEMBRANES

The interpretation of freeze-etching pictures of biological membranes is difficult but very important for the resulting informations. The results of our studies of various biological membranes led to the following conclusions: 1. The membranes are splitted during freeze fracturing and the visible membrane faces are views at one half of the membrane (from the membrane interior). 2. The two membrane faces which arise from the splitting of a membrane are different. In all cases there are more particles found on the face which is in close connection with the plasma [the (+)(-) distinction of the membrane faces]. 3. The number of particles at the membrane faces shows differences which may be in relation to the function of every type of membrane. A membrane model is proposed. © 1969 Springer-Verlag.