Magnetic plate stand

This is an inexpensive and easy-to-assemble magnetic plate stand for use with 96-well PCR plates. It uses 24 5/16 x 5/16 axially-magnetized cylindrical neodymium magnets (like these from K&J Magnetics) for use in magnetic bead assays. The beads are attracted to the sides of each well, allowing pipette tips to reach the bottom of the well without disturbing the beads. The plate has a notched profile to align fully-skirted plates, in addition to indentations to localize half- or un-skirted plates.

I've included two versions with different magnet stickouts -- the 3mm is good for general-purpose use, but for very low-volume cleanups (< 15 µL) the maximum magnetic field is above the meniscus, causing the beads to not adhere as well. The 1.5mm stickout version works better for these low volumes, but you need to be more careful with the pipette tips.