if you mean to store poured 55mm NGM plates, then we just buy storage boxes with clip on lids at the local supermarket. After trying out different sizes/shapes and brands, we ended up buying for the equivalent of 5€/$6 poly boxes that store 50 poured plates, are easy to clean and last. I don’t know how much racks cost, but probably at lot more than our boxes??
I mean NGM plates with worms. Our lab does not have air conditioning and the temperature can change significantly. Thus, we keep worms/plates in 15 or 20C incubators and have to transport them to the microscopes. Keeping plates on racks is the easiest option, especially if one has several petri dishes with the same strain as only the top plate requires labelling.
ah ok, I see what you mean. We too have our worms either in incubators (16 degrees) or in a separate ~20 degree room, so I made a few bespoke racks from acrylic sheet and rod bought off Ebay (but Amazon sell it too) for the 90mm/55mm plates…cost about 10% of the bought versions and needed just one evening drilling, sawing and glueing.
I guess if you need lots and have the budget, then buying ready made is the way to go.