Knowledge Base › Troubleshooting Atlas › Microtomy
Knife / blade marks (score lines)
Also known as: scores, tram-lines, longitudinal scratches
What it looks like
Straight scratches or splits running parallel to the cutting direction, along the length of the section.
Where it usually appears: Nicked blade, hard inclusions, or calcified/suture material.
Likely causes
- Nick or damage on the blade edge
- Hard particles: calcium, sutures, staples, dust
- Blade debris or dried wax on the edge
Immediate checks
- Shift to a fresh area of the blade
- Clean the blade edge
- Inspect the block for calcified or foreign material
Corrective action
- Replace the blade
- Surface-decalcify calcified areas if appropriate before re-cutting
Preventive action
- Remove sutures/staples at grossing
- Decalcify bony specimens adequately
- Change blades regularly
This atlas is for educational purposes for laboratory professionals. It does not replace your institutional SOPs, manufacturer instructions, validated protocols or pathologist judgment. Adapt any action to your laboratory and equipment.
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