Karter Scientific is a registered trademark in USA. To maintain quality control, authorized permission is required in the resale of our products. Karter Scientific liquid handling offerings include a full selection of sterile and non-sterile LDPE transfer pipettes. LDPE is non-toxic and chemically inert to biological fluids and most acids and can withstand a temperature range from -50°C to 90°C. Pipettes may be heat-sealed and frozen in liquid nitrogen for sample preservation.