Abstract: The invention relates to a process for obtaining preparations of toxoplasmas, improved for the diagnosis of toxoplasmosis by direct agglutination, said process comprising, in a first step, the inoculation in mice of a mixture of toxoplasmas and of sarcomatous cells, in a second step the inoculation in other mice of a mixture of sarcomatous cells infected with toxoplasmas coming from the mice of the first step and of non-infected sarcomatous cells, and finally the collection of the ascitic exsudate of these latter mice from 48 to 72 hours after inoculation.

Abstract: Systemic lupus erythematosus is diagnosed by contacting the blood serum of a patient with anaplasma antigen derived from a vertebrate infected by an organism of the genus Anaplasmataceae and thereafter contacting the antigen with an indicator for human immunoglobulin components.

Abstract: A method for quantitative propagation of hemotropic parasites, especially Babesia parasites, in vitro, Babesia-infected erythrocyte cultures are incubated in an environment of enhanced carbon dioxide tension wherein the culture medium overlay provides a barrier to oxygen transmission such that cellular hemoglobin is essentially maintained in its deoxy state. By varying environmental carbon dioxide tension, merozoite stages of the parasite are selectively reversibly induced to migration between residence in host cells or culture medium, rendering possible the isolation of infective antigenic merozoites in large quantities. Specific Babesia antigen is harvested in large quantity from the in vitro culture medium.