A test tube rack for supporting, storing and carrying a plurality of test tubes in a laboratory environment comprising a tray, a central support panel and/or lower support panel and a cover. The tray and cover are identical and interchangeable, and tapered for storage in nested stacks. Wells in the tray bottom are in alignment with corresponding openings in the central support panel and corresponding holes in the lower support panel and with domes in the cover, and serve to locate and retain test tubes within the test tube rack. The cover snap-attaches to the tray with at least one molded-in tab on the tray or cover which is received and frictionally retained by a corresponding well on the opposite element, thereby locating and securing the cover to the tray, and also locating and securing the central support panel between the tray and the cover. A dual-purpose support panel has manually removable perforated edges allowing it to serve either as a central support panel or, with the perforated edges removed, as a lower support panel. The test tube rack is preferably made of transparent injection-molded or thermoformed plastic.