Geeky Fridge Magnets




About: I like sewing and crafts,and trying new things. I'm vegetarian and always looking for new recipes. My cat's name is Mirko and likes to be in the centre of things, so you will see him in several of my instr...

In this instructable I will show you how to make refrigerator magnets for the lab geek. Why not decorate the fridge with petri dishes growing molds and bacteria.  Well maybe that is not such a great idea (don't worry, these cute magnets for the fridge don't really contain any cultures).

I work in a lab that does tissue culture and we had some old petri dishes lying around that we no longer were using, so I took a bunch home. I'm still not sure what to do with all of the dishes, though this seemed like a fun way to use some of them.

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Step 1: What You Will Need

  • Petri dishes - you can pick these up at science supply stores (for example)
  • Glue
  • Sharpies and paint
  • Neodymium magnets
  • white paper

Step 2: Pour Agar

Using sterile technique (just kidding) fill the bottom of the petri dish with glue, spread it out evenly to cover the whole plate with equal thickness.   Allow to cool and harden.

Step 3: Innoculate With Bacteria and Mold

I used sharpies to draw the bacteria and mold onto the surface of the glue.  In the first dish I tried to mimic a streak plate.  On the other dish I drew a colony of colourful mold radiating from the centre. 

Step 4: Genetically Engineered (glowing) Bacteria

I had some glow in the dark paint so I dabbed dots of paint onto the surface of the glue so that it looked like bacterial colonies transformed with bioluminescence genes.

Step 5: Evil Mutant Bacteria

For this last dish I wanted it to look like the bacteria was oozing out of the dish so I applied a blob of glue onto the surface as well as over the edge of the dish and then covered it with glow in the dark paint.

Step 6: Add Magnet

Once the dishes were decorated I added white paper to the back of the dish (otherwise you can see the magnet in behind), then glued the magnet on.  For the size of the dish I was using I needed a small neodymium magnet, you may need more than one for larger dishes.

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    14 Discussions


    4 years ago on Introduction

    I recommend to use some white double-sided adhesive tape on the dish, put the magnet on it and put some single-sided tape over it all...this magnet will never part by itself (depending on tape quality of course).


    1) single-sided

    2) magnet

    3) double-sided

    2 replies

    Reply 4 years ago on Introduction

    Of course the flatter the magnet is, the easier it is to fix the single-sided tape on top. But as neodym is so strong, there will be no problem taking a really flat one...perhaps if necessary larger but thinner like e.g. 10mm x 1mm!?!



    7 years ago on Introduction

    Hi, I am an admin in a geology lab workplace, so I am not overly sure if this would work, but I have seen small, round plastic containers at craft and dollar stores that are often used to hold "seed beads". They are quite cheap and kind-of look like petri dishes. It might be an option for those who want the look but not the cost of a specialty lab products store.

    1 reply
    action pig

    7 years ago on Introduction

    As a fellow lab rat (E-coli and yeast cultures) I applaud this idea. Although I would hate to take work home with me...