Sectioning protocols will vary with each histology department. The outline below summarizes the most widely accepted practices. Defining recuts, levels, deepers, and serial sections clarifies the protocols most often utilized.
Sectioning terminology
- Levels: Tissue sampling beginning with the first section, then collecting sections from consecutive ribbons, every 8-10 sections.
- LEVEL 1 - first section (section #1) off the first ribbon, length typically 8 sections; remainder of sections are discarded.
- LEVEL 2 - first section (section #9) off the second ribbon of same block, remainder of sections are discarded.
- LEVEL 3 - first section (section #17) off the third ribbon of same block, remainder of sections are discarded.
- Deepers or step sections: Tissue sampling at specific depths that will reveal deeper areas of tissue.
- DEEPER x1 - Discard first ribbon off block, collect section off next ribbon, repeat with more deepers.
- STEP SECTION x 2 - Collect section at 40 microns (this will vary!) deep each time; face into block a total of 40 microns (at 4 microns, that would be 10 revolutions of the microtome wheel), then collect section. Face another 40 microns and collect another section.
- Serial sections: Collecting every section from the tissue block. This sampling produces a copious amount of slides that create a complete "movie film" of the entire tissue sample.
- Recuts: Additional sections requested off the block without going deeper.
Specimen Type | Initial Cuts |
Single biopsy (shave or punch) | 3 levels |
All other biopsies | 2 levels |
Excisions | 1 level |
Cysts, lipomas | 1 level |
Nails | 4 charged slides total ( 2 for H&E, 2 for special stains) |
Skin with suspected infection | 4 unstained slides in addition to initial levels (for special stains) |