Growth of yeast cultures as in vitro model for investigating homœopathic medicines

Summary

1. The actions of homœopathic potencies of Pulsatilla on the growth rate of yeast cultures (Saccharomyces cerevisiae) were investigated as an attempt to confirm the sensitivity of this model recently claimed by Jones et al.

2. Yeast cells were grown in batch culture in the presence of potencies of Pulsatilla of the concentration range 2c to 19c. Growth was interrupted near the upper end of the exponential growth phase and total cell concentrations assessed by means of a Coulter Counter. The data were subject to statistical analysis.

3. Three different sets of treatments were applied: A 2c–10c, control B 11c–19c, control C 4c, 8c, 9c, control

4. The intention was to perform a repetition of the work by Jones et al. which in crucial features was to be as identical as possible. The tincture of Pulsatilla used in the preparation of all the potency sets was identical with the one used by Jones' team in their work. The method of preparation of the potencies was very similar to their approach. The dried yeast used in these experiments was a sample from the batch used by Jones' team.

5. The results obtained fail to show any effect of potencies of Pulsatilla on the growth rate of cultures of Saccharomyces cerevisiae.

6. Controls were unsuccussed distilled water. Each set was tested three times in separate experiments. Each treatment was represented by 6 replicates in experiments of type A and B and by 15 replicates in experiments of type C.