Isolation and preservation of Toxoplasma gondii.

Thirteen isolations of Toxoplasma gondii were made from 110 specimens of various human tissues and tissue fluids. Twelve of these were from lymph nodes and one from a specimen of cerebrospinal fluid; all isolations were from cases with dye test titres of 1/512 or more. A description of the deep freeze method used to preserve the T. gondii strains isolated is included. It is hoped that attempts at isolation of this organism will be made more frequently in future.