SIMILAR EFFECTS OF VARIOUS NEUTRAL SOLUTES ON THE SURVIVAL OF AEROBACTER AEROGENES AND OF RED BLOOD CELLS AFTER FREEZING AND THAWING.

Abstract

Aerobacter aerogenes from continuous culture is killed by slow freezing in buffer or by freeze-drying. Rapid freezing in liquid nitrogen results in 50 per cent survival if the organisms are suspended in distilled water, and almost complete survival if they are suspended in 10 per cent glycerol. Ten per cent solutions of some other polyhydroxy-compounds, sugars or of polyethylene glycol protect equally well1. The work recorded here extends the investigation to other, mainly non-hydroxylic, compounds. Like the sugars, these had already been tested on human red blood cells subjected to relatively slow freezing (various workers, references below) and it seemed possible that the response of A. aerogenes would not be very different from that of red cells.