Adjustable test tube holder

A test tube holder comprising:

• a base;
• a first support member defining an aperture therein, the first support member being coupled and rotatable with respect to the base between a first position, where the aperture is a first distance from the base, and a second position, where the aperture is a second distance from the base different than the first distance;
• and
• wherein the base defines a mounting aperture having a locking protrusion, wherein the first support member includes a rotating lug sized to be at least partially received within the mounting aperture and having a locking groove, and wherein the locking groove is positioned such that the locking groove engages the locking protrusion at predetermined rotational intervals as the rotating lug rotates with respect to the mounting aperture.

A test tube holder configured to support a combination of a first test tube type and a second test tube type, the test tube holder comprising:

• a base;
• a plurality of support members adjustably coupled to the base;
• a plurality of test tube stations, wherein each support member of the plurality of support members at least partially defines a unique portion of the test tube stations, and wherein each support member is adjustable between a first position wherein the unique portion of test tube stations is configured to support the first test tube type, and a second position wherein the unique portion of test tube stations is configured to support the second test tube type and
• wherein the base defines a mounting aperture having a locking protrusion, wherein the first support member includes a rotating lug sized to be at least partially received within the mounting aperture and having a locking groove, and wherein the locking groove is positioned such that the locking groove engages the locking protrusion at predetermined rotational intervals as the rotating lug rotates with respect to the mounting aperture.