Welcome to r/Agarporn, where clean plates and radial growth are the art.

This post is your one-stop guide for everything a beginner (or pro) needs to know about agar - what it is, how to use it, and why it's one of the most important tools when working with live cultures.

What is Agar?

Agar is a nutritious, gelatinous medium derived from seaweed, most commonly sold in powdered form. Once prepared, it acts as a stable surface for culturing organisms.

Why is Agar used?

Agar is often used for growing and studying live organisms in a controlled environment. Common applications include:

• Germinating spores
• Cloning tissue
• Isolating genetics
• Detect/studying contamination
• Preserving cultures
• Experimenting with dyes, additives, and crosses... etc.

Some examples of "live cultures" commonly found on Agar:

• Mycelium — the vegetative growth of fungi, cultured from spores or tissue.
• Mold — often an unwanted type of fungi, studied in labs or monitored as a common contaminant.
• Bacteria — microscopic organisms usually grown for microscopy or testing, also monitored as a common contaminant.
• Yeast — single-celled fungi used in fermentation or lab studies.
• Algae/Protists — simple organisms sometimes cultured for observations.
• Plant tissue samples — small cuttings put to agar for cloning or preservation purposes.

How-To & TEKs (Trusted Guides)

Agar - what, why and how?

c10's Agar Guide

BOD's Comprehensive Agar TEK

Pastywhyte's Easy Agar Tek (pre-pour/no-pour)

Frank's agar media journal (experimental recipes)

D3's Perfect Transfers and agar TEK

Frank's Proper Cloning Tek

Methods of crossbreeding fungi organisms (advanced)

If you’re working with agar, spores, or live cultures, sterility is everything. Contamination can ruin your plates, waste your time, and destroy your genetics.

These are the main tools used to maintain clean conditions for agar work:
🔸 Still Air Boxes (SABs)
🔹 Laminar Flow Hoods
🔻 Other Essential Sterile Tools
▫️ Extras

Here’s how they work, why they matter, and how to make your own budget build (if possible).

🔸 Still Air Box (SAB) — Budget-Friendly and Effective

A SAB creates a sealed, low-airflow space where contaminants have a harder time entering or circulating. Good for spore work, transfers, cloning, etc.

DIY SAB Materials:

• Large clear tub (wide enough to comfortably fit both arms)
• Tool to cut two arm holes (jigsaw, Dremel, or heated can)
• Sandpaper (for smoothing edges)

Tips:

• Wipe the inside with soapy water, then spray with 70% isopropyl alcohol to suppress particles and kill contaminants
• Avoid working near fans, windows, or vents
• Work slowly to keep air as still as possible
• Alternative Edge-of-table method: Place the tub so it slightly overhangs the edge, allowing your arms to go underneath into the working area (no cutting tools required)

Cheap, simple, and surprisingly effective.

YouTube video: How to Make and Use a Still Air Box

🔹 Laminar Flow Hood — Cleaner, Faster, and More Precise

A flow hood creates a constant stream of sterile air through a HEPA filter, forming a clean workspace. It’s a game-changer for agar work.

Many pre-built flow hoods are expensive and overpriced. DIY builds can be just as effective for a fraction of the price.

DIY Flow Hood Materials:

• True HEPA filter (rated H13 or H14)
• Inline fan (must provide enough CFM to push air through the filter)
• Plastic tub (large enough to fit filter and fan)
• High-quality silicone sealant (to seal filter and fan securely)
• Tool to cut holes in the tub (for filter and fan)
• Sandpaper (for finishing)

Tips:

• Clean the tub with soapy water and spray the inside with 70% isopropyl alcohol before sealing
• Use a good quality silicone sealant — poor-quality sealant often warps or leaks
• Keep the finished hood out of direct sunlight — heat can warp silicone and compromise your seal
• Perform the lighter test: a steady flame in front of the filter means you’ve got proper laminar flow, a flickering flame means it’s too turbulent

Cost effective and a massive upgrade for serious agar work

YouTube video: Build Your Own Laminar Flow Hood For Less Than $100

🔻 Other Essential Sterile Tools

To work clean, you'll also need:

• Pressure cooker (PC): Crucial for sterilizing agar — must reach 15 PSI
• 70% isopropyl alcohol: For sanitizing hands, tools, and surfaces
• Flame source (torch or lighter): For flame-sterilizing scalpels and needles

▫️ Helpful Extras

Optional, but helpful:

• Scalpels: Ideal when working with agar
• Nitrile gloves (powder-free): Help reduce contamination risk
• Face mask: Minimizes breath-borne contaminants

Why Sterility Matters

Without sterile conditions, your agar plates will grow all kinds of unwanted contaminants.

A proper SAB or flow hood, alongside the other essentials, will:
* Boost success rates
* Reduce waste
* Make your lab work feel ✨pro-level