Use of Perchloric Acid for Nucleic Acid Histochemistry in Mammalian Nerve and Liver Cells.

Abstract

The perchloric acid technique of Ogur and Rosen for differential extraction of pentose nucleic acid (PNA) and desoxypentose nucleic acid (DNA) was applied to formalin-fixed sections of spinal cord and liver of several mammalian spp. PNA was completely extracted from liver cells after 18 hours of treatment with 10% perchloric acid at 4[degree]C with no extraction of DNA as shown photometrically on Feulgen-stained sections. This treatment was ineffective for nerve cells. However, 12-hour extraction at 20[degree]C and 15-minute extraction at 37[degree] C removed PNA from nerve cells with no loss of DNA. Prolonged hardening of blocks in formalin rendered PNA refractory to such extraction. This procedure did not extract cytoplasmic protein, as seen in Millon-treated sections measured with a microphotometric technique. Cell structure was likewise unaltered and the extinction at 2537A, of ribonuclease-treated nerve cells and untreated striated muscle fibers, which contain no PNA, was unchanged by this method. It was suggested that this procedure could be employed to provide tissue "blanks" in u.-v. micro-absorption spectroscopy for PNA in tissue sections.