Rosette formation by peripheral lymphocytes.

In preparations of human peripheral lymphocytes suspended in serum absorbed with sheep red cells, up to 30% of the lymphocytes may make rosettes with sheep erythrocytes. Washed lymphocytes suspended in Hanks' solution make many rosettes if tested without delay. Such lymphocytes rapidly lose their capacity to make rosettes, but it can be restored by adding the serum of man or of the horse, rabbit or guinea-pig.