I'm running a somewhat high-throughput experiment on paramagnetic beads, and figured a 96-well-compatible magnet would be useful. Commercial versions (like this one from Thermo) can run into the $400 range, which was far more than I was willing to pay for. Turns out, you can do this in a 48-well plate format for about $15 in magnets along with a bit of filament.
It's hard to see the pull-down pattern in the pictures, but Dynabead M280s will pull up on the sides of the wells cleanly and rapidly, even at 10uL.
I modeled this on Tinkercad, so feel free to remix either here or there.
Attaching the Magnets
I designed this to use 5/16"x5/16" N48 cylinder magnets (ordered from Apex Magnets, although it's a fairly common size and you should be able to find these at most internet magnet purveyors). Worth noting that these things chip like crazy, so don't mess with them unless you need to.
Cyanoacrylate didn't provide a good enough hold, so I ended up using 2-part epoxy. A good way to do this:
- Lay out the magnets on a flat metal sheet in the correct pattern, test fit with your printed part
- Prep your epoxy, apply to the printed part where your magnets go. Don't add to much, it will get in the way of your plate wells.
- Invert printed part, apply to magnets, allow to cure.