Abstract: A test tube insert includes a flange having a width greater than a width of a mouth of a larger test tube into which the insert is to be inserted. The flange defines a first central opening. An annulus extends integrally downward from the flange. The annulus includes a fenestrated wall and a floor defining a second central opening. A small test tube body, smaller than the larger test tube, extends integrally downward from the floor of the annulus with the second central opening forming a mouth of the small test tube body. The test tube insert is disposed in the mouth of the larger test tube. Fluid is transferred through the central opening and the fluid fills the small test tube body of the test tube insert and flows through the fenestrated wall once the small test tube body is full into the larger test tube.

Abstract: A reagent tube configured with a stellated shaped pattern, on its bottom interior surface, configured to facilitate complete or near-complete withdrawal of fluid from the tube, via a pipette tip. The reagent tube may be used for transporting reagents and for carrying out processing operations on biological samples with the reagents, such as preparing polynucleotides extracted from the sample for amplification.