Evaluation of ethanol-fixed, paraffin-embedded tissues for proteomic applications

Proteomics. 2003 Apr;3(4):413-21. doi: 10.1002/pmic.200390056.

Abstract

We previously reported that ethanol fixation and paraffin embedding of tissues produce excellent histomorphology and good preservation of macromolecules. Here, we present a detailed evaluation of ethanol-fixed tissues for proteomic initiatives. When proteins were extracted from ethanol-fixed, paraffin-embedded prostate tissue, resolved by two-dimensional gel electrophoresis (2-DE), and stained by standard methods, several hundred protein molecules could be detected and successfully analyzed by mass spectrometry. Protein profiles obtained from ethanol-fixed tissues were highly similar to those observed from frozen tissues, in contrast to the poor protein recovery from formalin-fixed material. The protein content of specific cells that were microdissected from ethanol-fixed tissue sections using laser capture microdissection could also be successfully analyzed by 2-DE. We observed that eosin staining of tissue sections had a detrimental effect on protein separation, whereas hematoxylin staining had minimal consequence. In order to illustrate the applicability of ethanol-fixed tissues for proteomic discovery studies, we compared the protein profiles of patient-matched, normal prostatic epithelial cells and invasive adenocarcinoma cells obtained from ethanol-fixed, paraffin-embedded tissues. A number of differentially expressed proteins was discovered and identified by mass spectrometry. Immunohistochemical analyses performed on ethanol-fixed tissue sections were in agreement with the proteomic discovery findings. In light of these results, we conclude that ethanol-fixed tissues can be successfully utilized for proteomic analyses.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Electrophoresis, Gel, Two-Dimensional
  • Eosine Yellowish-(YS)
  • Ethanol
  • Gene Expression Profiling
  • Humans
  • Immunohistochemistry
  • Male
  • Mass Spectrometry
  • Microdissection
  • Neoplasm Proteins / analysis
  • Neoplasm Proteins / chemistry
  • Neoplasm Proteins / isolation & purification
  • Paraffin Embedding / methods*
  • Prostatic Neoplasms / chemistry
  • Prostatic Neoplasms / pathology
  • Proteomics / methods*
  • Staining and Labeling
  • Tissue Fixation / methods*
  • Xylenes

Substances

  • Neoplasm Proteins
  • Xylenes
  • Ethanol
  • Eosine Yellowish-(YS)