Overview: Your Four Options
There are four main ways to get your hands on live slime mold. Each has its advantages and drawbacks depending on your situation.
| Method | Cost | Reliability | Best For | Shipping |
|---|---|---|---|---|
| Science supply companies | $8-20 | Very high | Schools, researchers, serious hobbyists | Temperature-controlled, fast |
| eBay / online marketplaces | $5-15 | Variable | Budget-conscious hobbyists | Standard mail, variable quality |
| Educational kits | $15-35 | High | Beginners, families, teachers | Standard shipping |
| Wild foraging | Free | Low (unpredictable) | Experienced naturalists, adventurous types | N/A |
Option 1: Science Supply Companies
Dedicated science suppliers are the most reliable source for live Physarum polycephalum cultures. These companies maintain laboratory-grade stock cultures and ship them under controlled conditions to ensure viability.
Major Suppliers
| Supplier | Region | What They Sell | Price Range | Notes |
|---|---|---|---|---|
| Carolina Biological Supply | United States | Live cultures, sclerotia, classroom kits | $10-25 | The most established U.S. supplier. Ships year-round with cold/heat packs as needed. |
| Ward's Science | United States | Live cultures on agar | $12-20 | Popular with schools. Offers bulk discounts for classroom orders. |
| Southern Biological | Australia | Live cultures, sclerotia | AUD $15-25 | Best option for Australian customers. Ships domestically. |
| Blades Biological | United Kingdom | Live cultures | 10-18 GBP | Reliable UK supplier with fast domestic shipping. |
| CNRS / Scientific partners (France) | Europe | Sclerotia kits (via blobshop.fr and partners) | 5-15 EUR | Connected to Audrey Dussutour's research. Very popular in France. |
What to Expect
When you order from a science supplier, you will typically receive one of two things:
- Live culture on agar: A Petri dish or tube containing an active, growing plasmodium on nutrient agar. This is ready to use immediately. Simply transfer a piece to your own dish.
- Sclerotium (dried culture): A piece of filter paper or similar material with a dried, dormant slime mold on it. This is more durable for shipping and storage but requires rehydration and revival before it becomes active.
Live Culture or Sclerotium?
If you want instant results, choose a live culture. If you are ordering during summer heat or winter cold (when shipping conditions are harsh), a sclerotium is safer because it tolerates temperature extremes that would kill an active plasmodium. Sclerotia also store well if you are not ready to start immediately.
Option 2: eBay and Online Marketplaces
eBay, Etsy, and similar platforms have become popular sources for slime mold cultures, often at lower prices than dedicated science suppliers. However, quality varies significantly between sellers.
Tips for Buying on eBay
- Check seller ratings. Only buy from sellers with at least 50 positive ratings and a score above 98%. Slime mold is a niche product, so look specifically for reviews mentioning live cultures.
- Read the listing carefully. Make sure you are buying Physarum polycephalum specifically. Some listings sell other species or even just spores (which are very difficult to germinate at home).
- Ask about shipping method. A good seller will ship quickly (within 1-2 days of purchase) and use padded envelopes or small boxes. Avoid sellers who offer only economy shipping with week-long transit times.
- Prefer sclerotia for eBay purchases. Dried sclerotia survive standard mail much better than live cultures. A sclerotium in an envelope will arrive viable even after several days in transit.
- Avoid summer and winter extremes. Temperatures above 35 C or below 0 C during transit can damage even sclerotia. If possible, order during spring or fall.
- Check the return policy. Reputable sellers offer replacements if the culture arrives dead or fails to revive.
eBay Price Expectations
| Listing Type | Typical Price | What You Get | Reliability |
|---|---|---|---|
| Sclerotium on filter paper | $5-10 | One or two pieces of dried slime mold | Good if seller is reputable |
| Live culture on agar | $10-18 | Small dish with active plasmodium | Risky in extreme weather |
| "Starter kit" (sclerotium + oats + instructions) | $12-20 | Everything to get started | Good value for beginners |
| Bulk sclerotia (5+ pieces) | $15-25 | Multiple dried cultures for sharing or backup | Good for classrooms |
Option 3: Educational Kits
Educational kits are the best option if you are new to slime mold or buying for a child or classroom. They bundle everything you need into a single package with instructions.
What a Good Kit Includes
- A sclerotium or live culture of Physarum polycephalum
- One or more Petri dishes
- Agar powder or pre-poured agar plates
- Oat flakes for feeding
- Printed instructions or activity guide
- Sometimes: a magnifying glass, experiment cards, or maze templates
Notable Kits
- The Blob Kit (blobshop.fr): Associated with Audrey Dussutour's research in France. Contains a sclerotium, Petri dish, agar, oats, and a detailed booklet. Ships primarily within Europe.
- Carolina Biological Physarum Kit: A classroom-ready kit with multiple cultures, agar, and an activity guide. Designed for 15-30 students.
- Various Etsy kits: Independent sellers on Etsy offer creative kits with custom packaging and experiment ideas. Quality varies, so check reviews carefully.
Are Kits Worth the Extra Cost?
If you already have Petri dishes and agar at home, buying just a sclerotium is cheaper. But if you are starting from zero, a kit saves you the hassle of sourcing everything separately. For children and classrooms, the included instructions and activities add real value.
Option 4: Foraging in the Wild
Slime molds are found on every continent except Antarctica. If you enjoy nature walks, you can find wild slime mold and bring it home to culture. However, this approach is unpredictable and requires some knowledge.
Where to Look
- Dead logs and stumps: This is the single best place to find plasmodial slime molds. Look on the underside and in cracks of decaying wood, especially hardwoods like oak and beech.
- Leaf litter: Thick layers of damp fallen leaves, particularly after rain, can harbor plasmodia.
- Mulch beds: Garden mulch, especially bark mulch, is a common spot for Fuligo septica (the bright yellow "dog vomit" slime mold).
- Mossy areas: Moss-covered rocks and logs in shaded, humid environments often host small myxomycete fruiting bodies.
When to Look
| Season | What to Expect | Best Conditions |
|---|---|---|
| Spring | Good. Active growth after winter dormancy. | After warm rains, in shaded forest. |
| Summer | Variable. Too hot and dry in many regions. | After thunderstorms, early morning. |
| Fall | Excellent. Peak fruiting season for many species. | Humid, cool days in deciduous forests. |
| Winter | Poor in most climates. Nivicolous species near snow. | Mild, wet winter days in temperate regions. |
How to Collect
- Bring small containers (plastic boxes or bags) and a pocket knife.
- If you find a plasmodium (bright yellow or orange mass on wood), gently cut away the piece of wood it is growing on and place the whole thing in your container. Do not try to scrape the plasmodium off; it will be damaged.
- If you find fruiting bodies (tiny stalked structures), collect the piece of wood or bark they are attached to. Note that fruiting bodies contain spores, not active plasmodia, and germinating spores at home is very difficult.
- Keep the collection moist and out of direct sun during transport.
- At home, place the wood piece with the plasmodium into a Petri dish on a damp substrate. Add oat flakes nearby. If the plasmodium is healthy, it should begin exploring within 24-48 hours.
Important: Species Identification
Wild plasmodia are not always Physarum polycephalum. Many species look similar in the plasmodial stage. If your goal is to grow the well-studied Physarum polycephalum specifically, buying from a supplier is the only way to be certain of the species. Wild-collected specimens are still fascinating to observe, whatever the species turns out to be.
Comparison: Which Method Should You Choose?
| Priority | Best Choice | Why |
|---|---|---|
| Lowest cost | eBay sclerotium | $5-8 including shipping in most cases |
| Highest reliability | Science supplier (Carolina, Ward's, etc.) | Laboratory-grade cultures, guaranteed viability |
| Best for kids/beginners | Educational kit | Everything included, instructions provided |
| Classroom use (multiple students) | Science supplier bulk order | Multiple cultures, educational resources |
| Adventure and learning | Wild foraging | Free, educational, connects you to nature |
| Fastest delivery | Local science store or university | Some university biology departments share cultures |
Storing Your Purchase Before Setup
If you receive your slime mold but are not ready to start growing it right away:
- Live culture: Keep it in its sealed container at room temperature. Feed it a single oat flake every 2-3 days. It will survive like this for a week or two.
- Sclerotium: Store in a cool, dry place (not the refrigerator). A sclerotium can remain viable for months or even years if kept dry. See our storage guide for details.
Getting Slime Mold for Free: University and Community Sources
Beyond the four main methods above, there are free or nearly free ways to get slime mold cultures if you know where to ask:
- University biology departments: Many universities maintain Physarum cultures for teaching and research. If you contact a biology department politely and explain your interest, some professors or lab technicians will share a small sample. This works especially well if you are a student or teacher.
- Science clubs and maker spaces: Local science clubs, biology meetups, and maker spaces sometimes keep slime mold cultures as community projects. Members often share samples freely.
- Online communities: Reddit communities like r/slimemolds and various Facebook groups dedicated to slime mold enthusiasts sometimes organize culture exchanges. Members mail sclerotia to each other for the cost of postage.
- Natural history museums: Some museums with biology education programs maintain live slime mold displays and may share samples during events or workshops.
Shipping and Receiving Tips
No matter where you order from, here are practical tips for ensuring your slime mold arrives in good condition:
- Choose expedited shipping if ordering a live culture. Every extra day in transit increases the risk of the plasmodium dying from heat, cold, or starvation.
- Avoid ordering on Fridays. Packages shipped at the end of the week often sit in postal facilities over the weekend, exposed to uncontrolled temperatures.
- Open immediately upon arrival. Check the culture as soon as it arrives. If it is a live culture and appears dead (no yellow color, no movement after 24 hours), contact the seller promptly for a replacement.
- Have your setup ready. Prepare your Petri dish, substrate, and food before the culture arrives so you can transfer it immediately. See our growing guide for detailed setup instructions.
Once you have your slime mold in hand, head over to our complete growing guide to set up your first culture. With proper care and the right environmental conditions, your slime mold will be thriving within days.