1. A simple method for the long-term viable-preservation of samples of Leptospira suspensions is described. Quantities of about 25 μl., with the addition of 77·5 % glycerol, are introduced into capillary tubes, cooled slowly to −79° C. and stored at that temperature.
2. More than half the attempts were successful in re-establishing growth in culture after storage at −79° C. for periods up to 27 months.
3. The possibility that the method could be used for establishing ‘banks’ of standard Leptospira material for reference is discussed.