Sonification as a Means of Enhancing the Detection of Gene Expression Levels from Formalin-Fixed, Paraffin-Embedded Biopsies

We describe a novel approach for the isolation and quantification of mRNA from archival specimens by using oligo(dT)25 paramagnetic beads and the reverse transcription polymerase chain reaction (RTPCR). A preliminary study is conducted to evaluate experimental conditions and the effects of varied periods of sonification on the yield of mRNA isolated from formalinfixed, paraffin-embedded human biopsy samples. Validation of this approach will involve the comparison of observed b-actin gene expression levels among different samples from the same patient after various periods of sonification. The novelty of this method is that it offers a means of analyzing archival samples using semiquantitative RT-PCR following sonification-enhanced mRNA extraction. The utility of this protocol allows for gene expression studies to be done effectively using the formalin-fixed, paraffin-embedded archival samples that are commonly available in all hospital pathology departments.