Human lymphocyte and mouse erythrocyte rosettes. Optimization of the assay.

Rosettes formed between lymphocytes and unsensitized mouse erythrocytes not only detect a subset of normal b-lymphocytes, but furthermore seem to be of considerable importance in the differential diagnosis of various B cell malignancies. From a series of experiments aimed at optimizing this rosette test, we conclude: (1) Erythrocytes from different mouse strains vary in their affinity for lymphocytes; (2) Experimental conditions are less strict when testing chronic lymphatic leukaemia lymphocytes than normal lymphocytes; (3) Treatment with the sulphydryl compound aminoethyl-isothiouronium bromide, which enhances sheep erythrocyte rosette formation, has an opposite effect on mouse rosettes, and (4) Neuraminidase treatment of the lymphocytes is not necessary when optimal experimental conditions are used.