Electrophoretic Characteristics of Streptococci Exposed to High Frequency Fields,and Subsequently Injected into and Recovered from Rabbits

Evidence has been presented 1 that the cataphoretic mobility of a culture of streptococci could be changed by application of high frequency energy. These changes were transmitted to the subcultures of the organisms. By the use of this technic, therefore, it may be possible to determine whether the source from which a strain of streptococci has been isolated is the single factor which determines the results produced by injection of the strain into rabbits or whether, in order to produce these results, the cataphoretic mobility of the organisms must be of a specific value.

Each animal in these experiments received an intravenous injection of 7.5 cc. of a subculture selected from one of the tubes of a series exposed to the high frequency field. Cultures in “glucose-brain broth” and blood agar platings were made from the blood, brain, joints, and other tissues of the animals within 30 hours of the time of injection. In the experiments presented, pure cultures of streptococci, usually either green-producing or indifferent on plates, were obtained from one or more of the tissues of each animal. After 24 hours of incubation at 37°C., 2 cc. of such a culture in glucose-brain broth was centrifuged at 1400 r.p.m. for 10 minutes; it was then drained and the residue was suspended in distilled water. This suspension was used to obtain the cataphoretic velocity distribution of the organisms.

The results of the cataphoretic measurements have been presented as distributions of cataphoretic time, which is related to cataphoretic velocity by the equation:

in which tc is the cataphoretic time and u is the cataphoretic mobility.