High-quality glass test tubes, and plastic test tubes are designed and constructed for optimal performance and excellent resistance to industrial scientific chemicals. Sturdy construction from borosilicate glass delivers a great range of operating temperatures. These precision-molded test and sample tubes are suited to a wide variety of applications, and are available in round- or flat-bottomed models. Easy-to-read graduations and labeling with all models. Minimal thermal expansion gives these test tubes high resistance to temperature changes.