Various methods for collecting marine leprosy bacilli in pure form and in high concentration were tried and evaluated by comparative tests in rats. The following methods were tested (a) centrifugation (b)pretreatment with trypsin and then centrifugation and (c) pretreatment with trypsin followed by the Hanks concentration method. The following results were obtained.
The yield was 13% with (a), 21% with (b) and 11% with (c). In other words, the method of pretreatment with 0.1% trypsin for 1 hour at 37°C (b method) gave the best results. It was found that the activity of the bacilli was not affected by this treatment.