Fixed and paraffin-embedded tissues from pathology department archives can be available for RNA expression analysis. In this report, we show that RNA isolated from surgical or autopsy tissues, routinely processed by fixation and paraffin embedding, is not completely degraded. RNA fragments around 100-200 bases in length are still present even in organs late fixed and very rich in RNase, such as the pancreas. Here we describe a general protocol to obtain RNA from single 6-8-μm tissue sections. The RNA extracted can be analyzed for the presence of specific sequences by reverse transcription and amplification with the PCR. We studied the retinoblastoma gene expression in 38 human pancreas specimens from surgical or autopsy origin.
