A still air box, often shortened to SAB, is a simple way to reduce exposure to airborne contaminants while working with mushroom cultures. It gives you an enclosed workspace for inoculations and transfers without a fan, electricity, or a complicated filtration system.
The most important part of using a still air box is right in its name: keep the air still. A clean enclosure, an organized workspace, and slow movements all help limit the dust and particles that can reach exposed sterile materials.
This guide follows the printed instructions supplied with our Myco Labs Large Still Air Box, with additional tips for preparing your workspace and avoiding common mistakes.
What is a still air box?
A still air box is an enclosure with openings for your arms. You work inside it while the surrounding walls help shield your materials from room drafts and unnecessary air movement.
A SAB does not filter the air or make everything inside sterile. Instead, it helps create a calmer environment where airborne particles can settle and clean technique is easier to maintain. Your grain, culture media, and tools still need appropriate preparation, and you still need to protect exposed sterile surfaces.
Growers commonly use a SAB for:
- Inoculating grain jars and bags through injection ports.
- Working with agar plates and transferring mushroom cultures.
- Handling liquid culture jars and syringes.
- Performing small batches of grain-to-grain transfers.
For large open-bag transfers or frequent culture work, a suitable flow hood may make the workflow easier. A SAB is a practical starting point for smaller projects when you can comfortably fit and handle the materials inside.
What you need before starting
Prepare the items for your specific task before opening any sterile containers:
- A still air box on a stable table or countertop.
- Clean gloves and clean clothing or sleeves.
- A suitable surface cleaner used according to its directions.
- Clean disposable towels for wiping surfaces and spills.
- Your jars, bags, plates, syringes, or other culture materials.
- Appropriately sterilized tools or sterile disposable tools.
- Labels and a marker to record your work.
Our portable SAB kit includes a box, disposable nitrile gloves, an Eco-Cleanse sample spray, and a storage case. Check the directions on the cleaning product you receive: a ready-to-use sample and a separately purchased concentrate are not interchangeable without the correct dilution.
Step 1: Prepare a quiet, clean work area
Choose a clean, low-traffic room and a surface that is easy to wipe down. Avoid working where people are walking past, pets are moving around, or dust is being stirred up.
Wipe the table or countertop before setting up the box. Wash your hands and make sure your sleeves and clothing are clean. Put on clean gloves for the procedure.
Turn off nearby fans and avoid open windows or air blowing directly toward the box. A still air box works best when both the room and your movements inside the enclosure remain calm.
There is no need to turn the entire room into a laboratory. Focus on a clean surface, a quiet location, and a workflow that minimizes exposure of your sterile materials.
Step 2: Set up and organize the box
Place the SAB flat on your work surface and make sure it is stable. Arrange your materials before beginning so you do not have to search for tools halfway through a transfer.
Keep only the items you need inside the enclosure. Too many jars, bags, or tools make it harder to move carefully and increase the chance of bumping or reaching over an open container.
Think through the procedure while everything is still closed:
- Where will your starting culture sit?
- Where will the receiving plate, jar, or bag go?
- Can you reach the tools without passing over exposed sterile surfaces?
- Where will completed containers sit while you finish the session?
If you are new to the task, practice the motions with closed containers first. A short rehearsal often prevents unnecessary movement during the actual transfer.
Step 3: Clean the inside surfaces
Follow the cleaning directions supplied with your box and cleaning product. The printed Myco Labs SAB guide recommends lightly misting the inside surfaces with Eco-Cleanse, including the top, sides, and bottom, and allowing them to air dry for approximately 1–2 minutes before starting.
Use a light mist rather than soaking the enclosure. Cleaners belong on the surfaces being cleaned; avoid spraying directly into open plates, jars, grain bags, or cultures.
If you are using Eco-Cleanse concentrate, prepare it according to the current label for workspace cleaning. Follow any stated application and contact-time directions. The quick-start guide's waiting period is a setup instruction, not a guarantee that a surface has become sterile.
Wipe down the outside of items as appropriate before placing them in your workspace, while keeping filters and other components protected according to their instructions.
Step 4: Let the air settle
Once the box is cleaned and your materials are arranged, pause before opening anything. Your printed guide recommends letting the air inside settle for about 1–2 minutes after setup.
Loading supplies, moving the enclosure, or quickly inserting your arms can disturb the air. Give yourself a moment to settle into position, then begin with slow, deliberate movements.
Waiting is helpful, but it does not replace clean technique. A SAB contains ordinary room air, and contaminants can still be introduced by tools, gloves, container rims, or exposed materials.
Step 5: Work slowly and protect sterile surfaces
Slide your arms carefully into the arm openings. Keep containers closed until you are ready to use them, and close them promptly when the step is complete.
During culture work:
- Move smoothly rather than making quick sweeping motions.
- Avoid repeatedly pulling your arms out and pushing them back in.
- Keep fingers and unsterile tools away from sterile media and container interiors.
- Avoid reaching over open plates, jar mouths, or bags.
- Open containers only as much and as long as the task requires.
- Label completed work so you can track the culture, date, and batch.
For agar procedures, our guide to using agar plates explains the transfer process in more detail. The SAB supports that procedure; it does not replace tool sterilization or proper handling.
Keep flames outside the still air box
Never use an open flame inside a SAB. Heat disturbs the air, and flames can ignite flammable vapors or damage the enclosure.
If your procedure calls for flame-sterilizing a needle or tool, do it outside the box, away from cleaning products and any flammable vapors. Let the tool cool before returning it to the workspace or contacting the culture. Do not wipe a flame-sterilized tip with a nonsterile towel afterward.
Keep alcohol and ignition sources separated. Do not assume that a short waiting period makes accumulated alcohol vapor safe to ignite. Sterile disposable tools are another option when appropriate for your procedure.
Step 6: Clean and store the box after use
Remove your materials carefully when the session is complete. Close and label containers before moving them to their next stage.
Wipe up spills or residue with a clean disposable towel, then clean the inside surfaces according to the supplied directions. If you spill culture media during a session, pause with your containers closed and clean the spill before continuing.
Allow the enclosure to dry before folding or storing it. Keep it in a cool, dry place and use the storage case to protect it between sessions. Cleaning it after use makes the next setup easier, but you should still prepare and clean your workspace again before the next procedure.
Still air box vs. laminar flow hood
Both can help with clean culture work, but they use different approaches.
| Feature | Still air box | Laminar flow hood |
|---|---|---|
| Main approach | Limits drafts and air disturbance inside an enclosure. | Supplies filtered airflow through a defined working zone. |
| Power | A basic SAB needs no electricity. | Requires a powered fan or blower. |
| Working space | Limited by the enclosure and arm openings. | Depends on filter size and the usable clean-air zone. |
| Typical fit | Occasional plates, inoculations, and small transfers. | Frequent transfers, larger batches, and work needing more room. |
| Technique | Slow movements and protection of sterile surfaces remain essential. | Correct placement, airflow management, and protection of sterile surfaces remain essential. |
A flow hood does not automatically eliminate contamination either. Choose equipment that fits your workload, and learn the technique required for that equipment. Explore our flow hoods and clean room supplies if you are ready to expand your workspace.
Common still air box mistakes
Working beside a running fan
Room drafts can undermine the calm environment you are trying to create. Turn off nearby fans and choose a location away from direct airflow.
Overloading the enclosure
Crowding makes it difficult to work without bumping objects or reaching over open containers. Use smaller batches and leave enough space to move comfortably.
Starting immediately after setup
Loading and cleaning disturb the air. Arrange your materials, allow the air to settle, and then begin.
Treating surface cleaning as sterilization
Wiping the box or the outside of a jar does not sterilize the grain, culture medium, or tool. Those need their own appropriate preparation before the session.
Repeatedly opening containers
Plan your steps so sterile materials remain exposed for as little time as practical. Keep completed work closed while you handle the next item.
Spraying cleaner during an open transfer
Close containers before cleaning spills or refreshing surfaces. Do not spray into an active transfer or onto exposed culture media.
Frequently asked questions
Does a still air box make the air sterile?
No. A SAB helps reduce drafts and air movement. It does not filter the air or sterilize its contents, so clean handling and properly prepared materials remain important.
How long should I wait before working?
The supplied quick-start guide recommends about 1–2 minutes for the air to settle after setup and approximately 1–2 minutes for the lightly misted surfaces to air dry. Follow the cleaning product's directions as well, including any required contact time.
Can I use a still air box for agar?
Yes. It is a practical option for small agar projects when you use appropriately sterilized tools, limit exposure, and avoid touching sterile surfaces.
Should I attach gloves to the arm openings?
Use the box as designed. Disposable gloves worn on your hands and gloves permanently attached to an enclosure are different arrangements. This guide follows the supplied kit's instructions for sliding your arms carefully through its openings.
Can I put a fan or air purifier inside it?
Do not add a fan to a basic SAB. Its purpose is to keep air movement low. A filtered-air workstation is a different system and needs a suitable design to control airflow.
Why am I still getting contamination?
Review the full process: the cleanliness of your starting culture, preparation of the grain or media, tool sterilization, handling, and air movement. A SAB can reduce one source of exposure, but it cannot fix contamination that is already present. Our contamination identification and response guide can help you assess suspicious growth.
Build a calmer workspace for your next grow
Successful SAB work starts before the first container opens. Choose a quiet location, prepare your materials, clean the surfaces, and work with controlled movements. Keeping the process organized makes those habits easier to repeat.
Start with the Myco Labs Large Still Air Box kit, browse clean room supplies, and use our agar and contamination guides to build your skills one procedure at a time.