the answer is none
Test Tube brushes are used to easily clean the test tubes .
used to chemical test
this is an instrument in the laboratory that is used to clean various kinds of test tubes.
used to place the test tube . :D hahaha
it is use to hold the test tube
John Detours
Container of liquid/chemical
apparatus
A laboratory test where venous blood is clotted in a test tube is called a serum clotting test. Once the blood sample clots, it is centrifuged to separate the liquid portion (serum) from the clot, which can then be used for various diagnostic tests.
beaker,test tube,
A clamp or test tube holder is typically used to hold a test tube in distillation setups to secure it in place during the distillation process.