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

Author(s): Noguchi M, Furuya S, Takeuchi T, Hirohashi S

Publication: Pathol Int, 1997, Vol. 47, Page 685-91

PubMed ID: 9361102 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of fixative type, temperature and additive on DNA and RNA extraction and amplification from lung, colon, breast and stomach tumors.

   Summary of Findings:

   Formalin fixation at 4 degrees C or in the presence of EDTA increased the yield of high molecular weight DNA compared with room temperature fixation or fixation in formalin without EDTA. Fixation with methanol increased the yield of high molecular weight DNA compared to formalin fixation. The authors report that fixation with acetone or ethanol preserved high molecular weight DNA as well as methanol, but led to more shrinkage of the tissue. A 214 bp fragment of the p53 gene was amplified in all specimens fixed in methanol or formalin, regardless of temperature or additive. A 684 bp fragment of the p53 gene was amplified in 100% of methanol fixed specimens, 91% of specimens fixed in 4 degrees C formalin, 73% of specimens fixed at room temperature with formalin and EDTA, and 27% of specimens fixed in formalin at room temperature without EDTA. Amplification of p53 RNA was successful in all 3 methanol-fixed specimens but none of the formalin-fixed specimens, regardless of temperature or additive.

   Biospecimens

   • Tissue - Lung
   • Tissue - Stomach
   • Tissue - Breast
   • Tissue - Colorectal

   Preservative Types

   • Formalin
   • Other Preservative
   • Ethanol

   Diagnoses:

   • Neoplastic - Carcinoma

   Platform:

   Analyte	Technology Platform
   DNA	Electrophoresis
   DNA	PCR
   RNA	RT-PCR
   Morphology	Light microscopy
   Morphology	Macroscopic observation

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Preservation	Temperature of fixation/preservation	4 degrees C Room temperature
   Biospecimen Preservation	Type of fixation/preservation	Acetone Ethanol Formalin (buffered) Methanol
   Biospecimen Preservation	Fixative additive/buffer	EDTA Multiple concentrations evaluated None

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