A protocol for representative sampling of solid tumors to improve the accuracy of sequencing results.

Owing to spatial segregation of tumor subclones, solid tumor sampling using formalin-fixed, paraffin-embedded blocks is often inadequate to represent the genomic heterogeneity of solid tumors. We present an approach, representative sampling, to dissect and homogenize leftover residual surgical tissue prior to sequencing. We also detail optional tumor cell enrichment and DNA preparation. This method, applicable only to surgically removed tumors with leftover tissue, facilitates robust sampling to avoid missing or over-representing actionable variants. For complete details on the use and execution of this protocol, please refer to Litchfield et al. (2020).