The Laboratory Medium: Agar Formulas and Recipes

In the laboratory, we don’t just use “dirt.” We use a controlled biological substrate called Agar.

The type of agar you use dictates how your blob behaves: whether it searches for food, takes a nap, or grows into a massive city-sized network. Here are the three industry-standard formulas.

1. Non-Nutrient Agar (NNA)

This is the “Hungry Agar.” It contains no food, which forces the blob to move and search.

• The Ratio: 20 grams of granulated agar per 1 liter of distilled water (2% concentration).
• Use Case: Mazes, Tokyo subway experiments, and basic observation.
• Professional Tip: For high-speed kinematic studies, reduce the concentration to 12 grams/liter (1.2%) for a softer, wetter surface.

2. Oatmeal Agar (The “Oat Flan”)

This is the “Growth Agar.” It integrates the food directly into the floor.

• The Formula: 100 grams of blended oat flakes integrated into 1 liter of boiling 1% agar.
• The Process:
  1. Prepare a standard 1% agar (10g/L).
  2. Blend your oats into a fine powder.
  3. Slowly mix the oat powder into the boiling agar until it becomes a “cream.”
• Use Case: Fast biomass production. If you need a giant blob by next week, this is how you get it.

3. Water Agar (WA)

The “Isolation” medium.

• The Ratio: 1% agar in pure water.
• Use Case: reviving old

  sclerotium: A hardened, dormant state.

  or cleaning up a contaminated sample. The lack of nutrients prevents bacteria from growing faster than the blob.

Specialty Additives

If you want to push the boundaries of science, try these professional additives:

• MgCl2 (Magnesium Chloride): Add at 25 mM to increase the viscosity of the “slime floor.” This mimics tougher terrain and slows down the blob, making it easier to film its transport rhythms.
• Nile Red / Fluorescent Tracers: Used to visualize the “pulsing” inside the veins. (Note: These are for advanced lab work and require a fluorescence microscope).
• Salt (NaCl): Add 150 mM to create “repellent walls” that the blob will refuse to cross until it learns to ignore them.

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Keeper’s Warning: Never use “Nutrient Agar” (the kind used for bacteria). It contains beef extract or peptone which will cause mold to grow so fast it will likely kill your blob.

Ready to cook? See our Sterilization and Safety guide.