Optimization of RNA extraction from FFPE tissues for expression profiling in the DASL assay

Formalin-fixed paraffin-embedded (FFPE) breast tumor tissues are readily available and represent a largely untapped, vast resource for molecular profiling of clinical samples with long-term follow-up data. We have optimized the conditions and parameters that result ill the preparation of total RNA that is of the necessary quality,for use ill the DASL (cDNA-mediated annealing, selection, extension, and ligation) assay ill which expression of 502 genes are analyzed simultaneously using as little as 100 ng of input RNA.