Review on 📦 Heathrow Scientific HS29022G Assorted Polypropylene Products by Adam Gechem

I ordered these for my high school students and they are totally impractical for test tubes. I was looking for something that would wash and pack easily and fit into our small budget and I thought this would work well. As the students place their 15mL tubes on the rack and lift it, the tubes will fall out of the large holes on the opposite side. I thought I solved this problem by flipping the stands and using tubes that are slightly larger than the holes on the bottom so they can't fall through. This limited the students to only running four rehearsals at a time. When the students used the racks in this way, some of the tubes broke because they were so much smaller than the holes in the top that they could slide diagonally out of the rack as the students carried them back to their seats. The structure also prevents the solutions in the tubes from being seen while they are in the rack. So when the students had to compare the color of the solution in each tube, they had to alternately hold the tubes next to each other so they could record their observations. These racks are likely to work well with sealed conical tubes but are unsuitable for use with regular tubes. I've attached a plastic sheet to one side of the shelves for the students to use to keep the tubes from (hopefully) falling out.