In liquid chromatography, the syringe functions primarily as a pipette or liquid-transfer device that loads a sample loop. The same largely holds true for gas chromatography. The syringe generally does not take an active role in injection, which occurs only after the sample has been displaced from the syringe. These syringes are designed for the highest performance in applications such as liquid or gas chromatography and the handling of corrosive gases and liquids, radioactive materials, and sterile solutions. Syringes are gas-tight and leak-proof.