An automatic apparatus for extraction of cell suspensions by repeated freezing and thawing

Abstract

AbstractAn account is given of the construction and operation of a fully automatic apparatus in which the material is kept under agitation in a closed container alternately surrounded by hot and cold alcohol supplied from separate baths. The apparatus has the following applications in microbiology and cell physiology: Extraction of micro‐organisms and cell tissues by repeated freezing (F) and thawing (T) at variable temperatures and lengths of FT cycle. Extraction can be controlled automatically or manually. As a practical example of the use of the apparatus a description is given of the extraction of living virulent S. typhi bacteria. Studies of the reactions of living micro‐organisms and tissues under varying physical conditions (e.g. high‐ and low‐temperature resistance experiments, osmotic studies, thermal synchronization of bacterial cultures, etc.). If required, the normal gas mixture in the residual air space can without difficulty be replaced by other gases or mixtures such as CO2 or N2.