Karter Scientific Labware Manufacturing Co., Karter Scientific Labware Manufacturing is among the world leaders in plastic test tubes, culture tubes, polystyrene test tubes, polypropylene test tubes and printing. We produce a line of high quality low cost plastic test tubes and accessories. Also we offer the only test tube custom print facility, open to the general public, in the United States. We offer the widest selection of parts, lowest minimums, fastest shipping times, and the most customization options available.