Knowledge Base › Troubleshooting Atlas › Microtomy
Ribbon not forming
Also known as: sections not sticking together, no ribbon
What it looks like
Individual sections separate instead of joining edge-to-edge into a continuous ribbon.
Where it usually appears: Low humidity, static, dirty blade edge, or hard wax.
Likely causes
- Blade edge dirty or has wax build-up
- Very low workroom humidity / static
- Paraffin too hard (high melting point) for the room temperature
- Uneven block edges (not trimmed square)
Immediate checks
- Clean the blade edge with xylene-moistened cloth
- Breathe gently on the block face to add humidity
- Trim the block so top and bottom edges are parallel
Corrective action
- Switch to a paraffin grade suited to your ambient temperature
- Reduce static (anti-static measures, humidity control)
Preventive action
- Keep ambient humidity moderate
- Trim blocks square
- Use an appropriate paraffin for the season
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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