PCR Tube Magnetic Racks

thingiverse

I loved the racks designed by destroyer2012 - far superior to racks requiring gluing magnets, but I felt compelled to make some modifications: # 4-Tube PCR Magnet Rack This is a slight modification from https://www.thingiverse.com/thing:1132367 - in the original, spaces in the back of the rack are closed, so PCR tubes cannot be seen. I opened up the back so the tubes there are visible in the front. It holds 8 tubes total, with four tubes wide. Magnets used are the same as the original: combining a 0.5 inch magnet http://www.kjmagnetics.com/proddetail.asp?prod=B842 and a 0.75 inch magnet http://www.kjmagnetics.com/proddetail.asp?prod=BC42 makes a "synthetic" 1.25 inch magnet. The original suggests aligning the poles of the magnets, but I placed them N to S so they stick together and worked fine. # 6-Tube PCR Magnet Rack Expanded from the modified 4-tube rack, this now holds six tubes. The real benefit is that it fits a single 2 inch magnet https://www.kjmagnetics.com/proddetail.asp?prod=BY042, eliminating the need to fiddle with two magnets as in the 4-Tube rack. The fit for the magnets is tighter than the 4-tube rack, but they can be forced into place. It holds 12 tubes total, with six tubes wide. Spacing on both racks is nine millimeters (center to center), so they fit a multichannel pipette. # Magnet Shover The magnet shover does exactly that - it helps seat the magnets all the way into their slot. Once the magnets are secure, I set the rack magnet-side-down on a sturdy flat surface and push down with all my weight to get the magnet flush with the bottom of the rack. Next, I use the shover to push the magnet in until the shover is stabilized by the lip of the rack, then use it to seat that magnet all the way in.