Preservation of Toxoplasma gondii by Freezing
Don E. Eyles, Nell Coleman, D. J. Cavanaugh · Journal of Parasitology · 1956
Most investigators employing the conventional rapid freezing methods in alcoholdry ice mixtures have failed in efforts to preserve Toxoplasma gondii (Sabin, 1938, and a number of others including this laboratory). Manwell et al. (1945) did report partial success, but preservation was not demonstrated for more than a few minutes nor were the results consistent. Weinman and Chandler (1954) mentioned preserving T. gondii for 60 days at a temperature of 70? C., but provided no details of the technique used. Recently, Dr. Weinman has informed us that glycerol was used and that he has a paper on this subject in press. In our laboratory we have recently been successful also in the slow freezing of 7'. gondii in glycerol solutions. Our success has been consistent in contrast to our unsucccessful results with rapid freezing. To date we have shown that organisms may be preserved for periods up to at least 209 days, and it is the purpose of this paper to outline the methods employed and describe some of the factors influencing the degree of success.