I often see K’nex sets at second-hand stores like Goodwill or Salvation Army so I decided to see if K’nex can be co-opted for science and used them to build a test tube rack.

The upright K’nex rods support the structure, can be raised and lowered if needed for taller test tubes, and they serve as test tube drying pegs. Don’t forget to follow me on Twitter: https://twitter.com/steveschuler20