ACRIDINE-ORANGE - A FLUOROCHROME STAIN OF NUCLEIC-ACIDS FOR THE STUDY OF MUSCLE-CELLS AND NEURONS

  • 1 January 1985
    • journal article
    • research article
    • Vol. 141  (2) , 120-127
Abstract
Acridine orange renders nucleic acids fluorescent when forming complexes with them: DNA is colored luminous yellow while RNA is a brilliant orange. Its application to sections of muscle biopsies permits the identification of certain muscle fibers, recognized by their bright orange fluorescence which contrasts with the pale green of mature, normal myofibrils in 3 specific situations: denervation, regeneration following injury and the rapid growth and maturation of fetal muscle. Myopathic nonregenerative atrophy, as well as histochemical type-specific atrophies, do not exhibit this same orange fluorescence. Because neurons, particularly motor neurons contain large amounts of RNA (by contrast with glial cells which have very little) the application by acridine orange in the CNS might help in understanding the development of the fetal brain, the evolution of some neurologic diseases, and the maturation of brain tumors. Since the technique does not require the exclusive use of frozen tissues, but also may be applied to formalin-fixed tissue in paraffin sections, it is well adapted to the study of human tissue obtained at autopsy.