The Pathology Research Core at Mayo Clinic offers tissue handling services enabling preservation of the integrity of your samples. External site paraffin blocks can be re-embedded in new paraffin prior to sectioning. Frozen samples that are too small and thin to be handled and sectioned without the use of mounting media can be placed in base molds and snap frozen in optimal cutting temperature (OCT).
Heterogeneous frozen tissue blocks are enriched by physically dissecting the tissue pieces while keeping the tissues frozen. The use of pathologist-marked, hematoxylin and eosin (H&E)-stained tissues as a reference improves the percentage of either tumor or benign tissue preserved in the frozen samples.