Contrived reference materials are a convenient sample source to evaluate all steps in a CGP workflow whether in optimization, validation, or proficiency testing. Their advantages are clear; first, they are readily available and consistent in yield and variant composition. In addition, they are highly multiplexed, making validation of the analytical part of CGP more efficient and cost effective than using remnant patient samples. Finally, complex, difficult to call variants can be easily included to critically analyze the bioinformatics as well. Formalin fixed and paraffin embedded (FFPE) samples are a common, yet challenging type of patient sample in CGP. DNA extracted from FFPE is often highly cross-linked, degraded, and fragmented. Yield from patient samples can also be limited, thus optimization of extraction in regard to amount and quality of DNA is crucial to the success of downstream analysis. Here we describe the evaluation of Seraseq FFPE Solid Tumor Reference Material.