MBP Capless Microtubes by Molecular Biology Products are clear polypropylene tubes without attached caps in 0.5 mL, 1.5 mL and 2.0 mL sizes. The 0.5 mL tube is compatible with the ABI-310 instrument, and the 1.5 mL tube is boil-proof. Capless tubes suit racks, trays and instruments where a hinged lid would get in the way. Tubes are non-sterile and packed 500 per unit.