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.
- 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; rest of sections are discarded.
- LEVEL 2 - first section (section #9) off the second ribbon of same block, rest of sections are discarded.
- LEVEL 3 - first section (section #17) off the third ribbon of same block, rest 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.
|Single biopsy (shave or punch)||3 levels|
|All other biopsies||2 levels|
|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)|