Abstract: Disclosed is an improved microcentrifuge tube (10). One improvement is a recessed well (20) within the top of the the lid (16) of the tube into which an identifying disk (22) is placed. Another claimed improvement is an expanded lower circumference (25) of the lower portion of plug (24) extending down from the bottom of the top (16) of the tube and an inwardly directed protrusion (26) on the inner surface of the top portion of the tube such that the expanded circumference (25) at the lower portion of the plug (24) fits under the inwardly directed protrusion (26) when said plug is inserted into the opening of the tube thus securing the lid to the top of the tube.