A test tube holder and tray assembly designed for use with a dri-bath incubator. The test tube holder comprises a top shelf which comprises a rigid top plate and a sheet of flexible material secured to the rigid plate having a second plurality of openings which are aligned with the openings in the top plate. The openings in the elastomeric material are slightly smaller than the test tubes such that when test tubes are placed therethrough a frictional engagement is provided so as to maintain the test tubes in the desired position. A bottom shelf is spaced from the top shelf and secured thereto. A tray is provided for holding the test tube holder and allows pre-positioning of test tubes therein so that the test tube holder and test tubes placed therein can be used directly with a dri-bath incubator.