Hold the wire handle at its widest point so that one side of the handle rests against your palm and the other side rests against your curved fingers. Rest your thumb on top of the handle to steady it and keep the jaws vertical.
Squeeze the sides of the handle together to open the jaws.
Place the jaws vertically around the test tube so that the top of the jaws is roughly 1 inch below the tube’s opening. Relax your grip on the handle to close the jaws. Confirm that the jaws are clamped fully and securely around the test tube before attempting to move it.
Release the test tube by lowering it carefully into a test tube rack and gently squeezing the handle of the tongs.