Abstract: An ultracentrifuge with a snap can and a tool for removing or installing the snap cap. The tool also is formed for installing and removing screw caps from centrifuge tubes, test tubes or the like. The ultracentrifuge tube has a balanced positive securement structure with a support collar that supports the tube independently of the cap securement structure. The tool has manually grippable, elongated body constructed of a semi-rigid material, and one end of the tool body includes a slot and a tab protruding from the tool end directly above the slot. The tool tab is formed to engage the top of the snap cap when a pry lip of the snap cap is inserted into the slot. The user can swing the tool up to unsnap the cap from the tube. The opposite end of the tool includes an open ended socket dimensioned and tapered to grippably receive the outer circumferential perimeter of a screw cap for a centrifuge tube thereby facilitating easy removal or installation.