Sectioning is the process of cutting tissue into thin slices. Tissue is typically embedded with optimal cutting temperature (OCT) or paraffin prior to being sectioned. These sections can be mounted on a variety of slides, or researchers can request sections be placed in 1-2 milliliter tubes for subsequent RNA, DNA or protein extraction. Sections from both whole blocks and tissue microarrays can also be generated.
Frozen tissues are sectioned using Leica cryostats, and paraffin tissues are sectioned using Leica microtomes. These sections are mounted on slides for hematoxylin-eosin (H&E) staining, immunohistochemistry, in-situ hybridization or laser-capture microdissection. Cut cryosections can also be placed in micro centrifuge tubes for subsequent extraction of protein or nucleic acids.