Human lymphoblastoid cells in long-term cultures: electron microscopic study

Fine structure of lymphoblastoid cell lines (LCL) derived from leukocytes of three patients with acute myelosis and one patient with undifferentiated acute leukemia were studied repeatedly by electron microscope. The majority of cells in all lines was of the same primitive lymphoblastic type as refered to in literature regardless to their origin. Morphology of the cells did not change with time of cultivation for several months, by freezing and thawing and by new recultivation after prolonged cryopreservation. No morphologic signs of contamination by viruses were found. No evident morphologic signs of differentiation to mature granulocytes or "mature" lymphocytes or plasmatic cells were observed.