The growth zone of lymph node tissue culture from various leukemias was observed by the clinical tissue culture and fluorochrominized tissue culture both devised in our laboratory, and the following results were obtained.
1) In the clinical tissue culture, the cells in the growth area of acute leukemia were extremely dense and the boundary of the growth area was sharply defined. In chronic lymphatic leukemia and monocytic leukemia the growth pattern was somewhat similar to that of acute leukemia.
2) In the fluorochrominized tissue culture, the growth area of lymph node tissue culture of lymphatic leukemia, revealed yellow fluorescence owing to the yellowish hue of lymphatic cells, while in myelogenaus leukeima, the central area of growth zone displayed greenish color owing to the immature cells and the peripheral area presented reddish orange hue resulting from the fluorescence of granules of the mature cells. In monocytic leukemia, the growth zone showed such various colors as green, yellow and reddish orange because of the fluorescence of monocytic cells and lymphocytes.
3) Accordingly, by the pattern and fluorescence of the growth area, the differential diagnosis of various leukemias could be made with certainty at low magnification by fluorescence microscopy