Sterilization and Safety: Standard Lab Protocols

To keep a Happy Blob, you must keep a Clean Lab. While slime molds carry their own natural antibiotics, they can still be overwhelmed by common household molds and “sludgy” bacteria.

Here is how to ensure your equipment is 100% sterile.

1. The Professional Standard: Autoclaving

In the lab, we use an autoclave. At home, a pressure cooker is your best friend.

• Pressure: 15 PSI (Pounds per Square Inch).
• Temperature: 121°C (250°F).
• Time: 40 minutes.
• Process: Place your agar-filled jars (loosely capped!) into the cooker with an inch of water. Once the pressure hits 15 PSI, start your timer.

2. The Microwave Method (Quick & Dirty)

If you don’t have a pressure cooker, you can use a kitchen microwave and heat-resistant glass.

1. Mix your water and agar powder.
2. Heat on High for 1 minute until it starts to boil.
3. Continue heating at 1-minute intervals on Medium power until the liquid is perfectly clear.
4. DANGER: Wait 2 minutes before opening the microwave. Superheated agar can “explode” (boil over violently) when you move the jar.

3. The “No-Autoclave” List

Crucial Warning: Do not put these items in an autoclave or microwave. They will melt, release toxic fumes, or ruin your machine.

• Lego® Bricks: Use 70% Isopropyl Alcohol to wipe them down instead.
• Plastic Petri Dishes: Most are single-use and pre-sterilized. Heating them will turn them into a puddle.
• Plastic Forceps/Tweezers: Many are not heat-resistant. Use stainless steel tools if you plan to flame-sterilize them.

4. Keeping Your Surfaces Clean

The “Work Area” is where most contamination happens.

• 70% Ethanol / Isopropyl Alcohol: This is the laboratory gold standard. Wipe your table, your gloved hands, and your jars before opening them.
• The 10% Bleach Soak: If a culture gets a bad infection, soak the entire dish in a 10% bleach solution for 2 hours before throwing it away. This kills any spores so they don’t infect your other blobs.

5. Personal Safety

• Heat: Sterilized agar is a viscous liquid at 100°C. It sticks to skin like lava. Wear thermal gloves.
• Fumes: When cleaning with alcohol or bleach, ensure your room is well-ventilated.

Pro Tip: Professional researchers always work near a Bunsen Burner or in a Laminar Flow Hood. The heat from the flame creates an “updraft” that prevents dust and spores from landing on your open petri dish.

Clean agar ready? Now learn how to Transfer Your Blob safely.