Sterile Technique and the Still Air Box
Clean technique is the biggest factor in avoiding contamination. Learn the core habits and how to build and use a still air box for home lab work.
Why sterile technique matters
Most early failures come from contamination, and clean technique is the single biggest factor in avoiding it. The goal is simple: keep unwanted moulds and bacteria out of your cultures and grain.
The core habits
- Work in still air, away from draughts, fans, and foot traffic.
- Wipe surfaces, gloves, jars, and syringes with 70% isopropyl.
- Flame scalpels and needles when working on agar or transferring.
- Do not breathe or talk over open containers.
- Let sterilised jars cool fully before opening them.
Building a still air box
Take a clear plastic storage tote, lay it on its long side, and cut two arm holes on the front about a shoulder-width apart. Wipe the inside with 70% isopropyl before each session, place your cooled jars and tools inside, and work slowly so the air stays settled. It is a cheap, effective alternative to a flow hood for home growers.
Working cleanly
Tie back hair, wear clean clothes, and keep the room dust-free. Slow, deliberate movements settle the air rather than stir it. A vigorous, healthy culture also helps by colonising faster than contaminants can establish.
