Killing activity from lysed kappa particles ofParamecium

Abstract

Lysis of stock 7 killers with ½% sodium deoxycholate, yields preparations with one half as much killing activity as homogenates, while lysing virtually all of the bright particles known to have killing activity in homogenates. The killing activity which persists is associated with particles which sediment at the same rate as the refractile bodies, the only visible remnant of the bright particles. It is concluded that killing activity is probably associated primarily, if not exclusively, with the refractile bodies of the bright kappa particles. Partially purified killer particles when stored at 27° C. for more than one day, progressively lose their ability to produce spinning of sensitives but retain their ability to produce paralysis. Loss of activity in crude preparations of refractile bodies kept 2 hours at 31° C. can be retarded by homogenates of either killers or sensitives.