Electron Microscopic Study of Human Basophils

Electron microscope studies were carried out on human basophils obtainedfrom peripheral blood and thoracic duct lymph. Delineation of the cells inthick sections was facilitated by staining with Toluidine Blue, which impartedthe characteristic purple-red color to the granules. The cytoplasm containsmany of the organelles seen in other cells, including a small Golgi apparatus,centrioles, mitochondria, fibrils and microtubules. Ribosomes and rough ERare rarely encountered. Basophil granules are surrounded by a unit membraneand contain particles which are uniform in size within the same granule butwhich vary in size in different granules within the same cell. Some granulesreveal a homogeneous texture and/or "myelin" figures. The appearance of mostbasophil granules differs from the ultrastructure of human mast cell granulesreported to date. It is suggested that the difference in fine structure may reflect a difference in the chemical constituents of the granules.

Submitted on September 20, 1966 Accepted on January 9, 1967