Definition: Viability refers to whether spores or mycelium are still alive and capable of growth under appropriate conditions. It does not guarantee vigor or speed—only the potential to grow.
Why it matters
- Helps set expectations for germination and colonization.
- Guides storage choices and refresh cycles for research collections.
- Reduces wasted time by screening materials before downstream work.
How viability is assessed (overview)
- Microscopy: Look for swelling spores and early germ tubes in clean mounts.
- Agar plate spot: Place a tiny sample on sterile, minimal agar. Observe for distinct mycelial growth radiating from the inoculation point.
- Mycelial transfers: For existing cultures, small transfers to fresh media can confirm ongoing metabolic activity.
Key factors that degrade viability
| Factor | Effect |
|---|---|
| Heat stress | Denatures proteins and damages membranes, reducing germination potential. |
| Excess moisture | Encourages bacteria and premature metabolic activity that exhausts reserves. |
| UV / light exposure | Damages nucleic acids and impairs enzymatic pathways. |
| Time & oxygen | Natural aging and oxidative damage gradually reduce survival. |
| Poor sanitation | Contaminants dominate early growth phases, masking true viability. |
Storage considerations
- Cool, dark, dry: Stable, moderate-cool temperatures and low humidity slow degradation.
- Minimal handling: Limit thaw–refreeze cycles and temperature swings.
- Labeling & records: Track dates and conditions to predict refresh needs.
Legal & safety: This page supports lawful research on edible and otherwise legal fungi. Always comply with local regulations and laboratory safety standards.