Abstract
The two-wave-length-scanning method in Feulgen cytophotometry was used to study gliogenesis in the human embryos and human fetuses to which 3H-thymidine autoradiography cannot be applied. Various amount of nonspecific light loss was contained in the tissue section of the nervous system. Elimination of non-specific light loss by the two-wave-length-scanning method enabled us to perform accurate measurement of DNA content in an individual nucleus. By this method, proliferating glioblasts could be recognized as cells containing more than diploid DNA amount. As a result, it was concluded that gliogenesis started in the spinal cord between 7th and 8th week in gestational age, and in the cerebral hemispheres between 12th and 20th week in gestational age.
