Abstract
Blastoid cells were found after initial Ficoll-Isopaque gradient centrifugation for mononuclear cell separation of normal human peripheral leukocytes. Both T and B cells were found in blastoid forms in rosette separations : T cells by neuraminidase-treated sheep red blood cells and B cells by yeast with human complement. Furthermore, the blastoid cell count increased after the second Ficoll-Isopaque gradient centrifugation. No blastoid forms were found concurrently in heparinized and non-heparinized blood in the same subjects. These observations seem to indicate that Ficoll-Isopaque probably induces blastformations in lymphocytes.
