Molecular information obtained from radiobiological tissue archives: achievements of the past and visions of the future.

Radiobiological archives have not been overwhelmed by applications to use their stored tissue materials, in part because of lack of technologies to conduct quantitative analysis of the tissues. Over the last decade, advances in methodology have made it possible to routinely extract both DNA and RNA from archival materials. The quantitative analysis of gene expression by reverse transcription real-time PCR (QRT-PCR), and of gene copy number by array-based CGH (aCGH), are now firmly established methods for the study of tissue samples stored as paraffin blocks. More recent developments in proteomic technology have enabled the extraction of proteins from formalin-fixed paraffin-embedded (FFPE) tissue samples. These protein extracts have been used to produce quantitative data by Western blotting and even to identify proteins through LC/MS analysis. The development of applications using gel-based proteomics (2D/MS) is still a future challenge. This report gives an overview of the methodology already applicable on FFPE tissue, as well as the novel technologies to be used in the future research. Our goal is to collect existing animal and human tissue samples for use by the radiation biology community, to test new technologies for preparation of material from tissue samples, and to actively pursue materials arising from ongoing research.