Article Text

other Versions

PDF
Preservation of nucleic acids and tissue morphology in paraffin-embedded clinical samples: comparison of five molecular fixatives
  1. Synnöve Staff1,2,
  2. Paula Kujala3,
  3. Ritva Karhu4,
  4. Annika Rökman4,
  5. Joanna Ilvesaro3,
  6. Saara Kares3,
  7. Jorma Isola1
  1. 1Laboratory of Cancer Biology, Institute of Biomedical Technology, BioMediTech, University of Tampere, Tampere, Finland
  2. 2Department of Obstetrics and Gynaecology, Tampere University Hospital, Tampere, Finland
  3. 3Fimlab Laboratories, Tampere University Hospital, Tampere, Finland
  4. 4Laboratory of Cancer Genetics, Tampere University Hospital, Tampere, Finland
  1. Correspondence to Professor Jorma Isola, Laboratory of Cancer Biology, Institute of Biomedical Technology, BioMediTech, University of Tampere, Biokatu 6, Tampere 33521, Finland; jorma.isola{at}uta.fi.

Abstract

Formalin fixation preserves tissue morphology at the expense of macromolecule integrity. Freshly frozen samples are the golden standard for DNA and RNA analyses but require laborious deep-freezing and frozen sectioning for morphological studies. Alternative tissue stabilisation methods are therefore needed. We analysed the preservation of nucleic acids, immunohistochemical staining properties and tissue morphology in paraffin-embedded clinical tissue samples fixed with Z7, RCL2, PAXgene, Allprotect and RNAlater. Formalin-fixed and deep-frozen samples were used as controls. Immunohistochemical analyses showed good preservation of antigenicity in all except Allprotect and RNAlater-fixed samples. RNA quality, based on RNA integrity number value by Bioanalyzer, was comparable with freshly frozen samples only in PAXgene-fixed samples. According to quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analyses, RNA from PAXgene samples yielded results similar to freshly frozen samples. No difference between fixatives was seen in DNA analyses (PCR and real-time PCR). In conclusion, PAXgene seems to be superior to other molecular fixatives and formaldehyde.

  • Fixation
  • Morphology
  • Immunohistochemistry

Statistics from Altmetric.com

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.