The Test Tube. The tube comes in 12x56 mm 3 ml cylindrical flat bottom, 13x75 mm or 12x86 5 ml cylindrical, with rim, 16x60 mm 5 ml cylindrical flat bottom, 16x100 mm 10 ml cylindrical, 16x100 mm 10 ml conical. All of which are with rim, and graduated in polystyrene.