Microcentrifuge Tube. MER 229443 1.5mL Microcentrifuge Tube, Snap Cap, Polypropylene, Natural, Conical Bottom, Graduated, CS Add to Cart Add to List. TMO362800-0020 - Sigma-Aldrich. Nalgene® Natural Micro Packaging Vial polypropylene copolymer, vial volume 2.0 mL, conical bottom, self-standing, external thread, untreated,