Syringes and Needles

A syringe is a simple pump consisting of a plunger that fits tightly in a tube to assist in pushing liquids or solids into objects through a needle, tubing or nozzle. Needles have varying gauges and lengths depending on use. Syringes can be disposable all-in-one with needles or the plungers or tips can be separate. The barrels of syringes are made of transparent plastic or glass with graduation marks to indicate the volume of fluid. The most common needles types are polypropylene slip hub and luer lock hub. The former work with all types of syringes and slip over the barrel with compression for easy installation. Luer lock hubs are specific to the barrel as they use threads to screw on, which forms a leak-free connection. Multishot needle syringes are reloaded from a built-in container after each use. Dental syringes are breech-loaded with a sealed cartridge containing the anaesthetic solution. In medical facilities, shorter needles are ideal for giving injections just under the skin while longer ones can get past muscles. In laboratories they are used to measure and transfer solvents and reagents when there is no need for precision. Glass syringes are ideal for injecting samples for gas chromatography and mass spectrometry.