Modified formalin and methanol fixation methods for molecular biological and morphological analyses

Pathol Int. 1997 Oct;47(10):685-91. doi: 10.1111/j.1440-1827.1997.tb04442.x.


Several simplified fixation methods were examined to determine their suitability for both molecular biological analyses and morphological study. Fixation with 10% v/v formalin alone at 4 degrees C and containing 5 mmol/L ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA) at room temperature preserved significantly more high-molecular-weight DNA than 10% v/v formalin fixation at room temperature. The morphological differences between tissues fixed using these modified formalin fixation methods and conventional 10% v/v formalin fixation were negligible. Of the dehydration fixatives tested, 100% methanol did not cause regional differences due to artificial tissue shrinkage and the morphology of sections prepared by methanol fixation was preserved consistently better than that of acetone- or ethanol-fixed sections. All three dehydration fixatives preserved relatively higher-molecular-weight DNA and RNA, compared with formalin. Cold formalin, formalin containing EDTA at room temperature and 100% methanol are recommended as standard and additional fixatives routine clinicopathological laboratory use.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast / chemistry
  • Breast Neoplasms / genetics
  • Colon / chemistry
  • Colonic Neoplasms / genetics
  • DNA / analysis*
  • Fixatives / pharmacology
  • Formaldehyde / pharmacology*
  • Gastric Mucosa / anatomy & histology
  • Humans
  • Liver / chemistry
  • Lung / chemistry
  • Lung Neoplasms / genetics
  • Methanol / pharmacology*
  • Polymerase Chain Reaction
  • RNA / analysis*
  • Stomach / anatomy & histology
  • Stomach / chemistry
  • Stomach Neoplasms / genetics
  • Tissue Fixation / methods*


  • Fixatives
  • Formaldehyde
  • RNA
  • DNA
  • Methanol