Staining of paraganglionic cells with lead hematoxylin

Lead hematoxylin staining in most paraganglionic cells is too faint to be observed in the light microscope (LM). Paraganglionic cells which appear stained (LM) are also known to contain more and larger specific granules (as seen in the electron microscope, EM) than those paraganglionic cells remaining unstained (LM). However, also specific granules in lead hematoxylin-negative paraganglionic cells (LM) bind lead ions (EM), which behaviour is the basis of lead hematoxylin staining. It is concluded that lead hematoxylin stains matrix material of specific granules but the amount of granule material mostly is too small to yield colour intensities to be observed in the LM.