Test tube racks are laboratory equipment used to hold upright multiple test tubes at the same time. They are most commonly used when various different solutions are needed to work with simultaneously, for safety reasons, for safe storage of test tubes, and to ease the transport of multiple tubes. Test tube racks also ease the organization of test tubes and provide support for the test tubes being worked with.
In this case, the medical equipment supplier just designed a test tube rack especially for every ward of the hospital. On top of the rack, there are cards recording the names and bed no. and tube numbers. The test tubes of one patient are put in one column. Nurses can insert the cards which record the sampling time into the bottom of the rack box. Both sides have slots and can hold documents.