Dispense tracker - multiwell plate

Very easy to lose track when dispensing things manually into a multiwell plate with shell vials; rows and columns can easily be confused once one gets into the middle of the plate. This is a very simple "dispense tracker" which I use to prevent any mistakes - basically it's moved down as one dispenses the plate so that we're always dispensing against it.

One for multiwell with 30 mm vials and another for 40 mm vials. I print these in polypropylene so they are a litte more chemical-resistant, and I use curing glue to assemble the pieces (note that normal contact glue does not work very well with polypropylene).