[Simple method for preservation of bacteria in small portions (author's transl)]

A method of maintaining micro-organisms in small portions is described. The microbial suspensions to be preserved are transferred into small PVC tubes, which are then heat-sealed in small segments. Care must be taken to ensure that the segments are not overfull, otherwise the seams may burst upon freezing. The segments are then transferred strainwise to small propylene test tubes for deep-frozen storage in an electric freezer at -90 degrees C or in liquid nitrogen at -195 degrees C. The viability of the micro-organisms thus treated is fully comparable with that obtained by other methods of deep-freezing. A brief account is given of how the micro-organisms can be recultured from these segments. The above method is particularly suitable when periodical subcultures of a large number of strains have to be prepared over a fairly long period of time. The suppliers of the materials used are indicated.