Effects of temperature and time on the infectivity of Cryogenically preserved samples of Anaplasma marginale- infected erythrocytes.

The effects of temperature (25 C) and time (2, 4, 6, 8, 12, 24, 48, 72, 96 hours and 5, 13, and 19 days) were determined on thawed samples of Anaplasma marginale-infected erythrocytes cryogenically preserved with dimethyl sulfoxide and frozen in liquid nitrogen. Inoculation into splenectomized calves indicated that infectivity was not destroyed by either time or temperature from 2 to 72 hours, but was destroyed at 96 hours. The incubation periods of the disease in inoculated splenectomized calves increased in proportion to the length of time the samples were held at 25C.