The Sample Injection Valve enables small liquid samples to be injected into microfluidic systems without the sample passing through the pump. The liquid reagent is loaded onto the sample loop via a luer port. The loop is then switched into the flow stream and the sample flows into the microfluidic system. With a port-to-port volume of <5µl the Sample Injection Valve is one of the smallest manual injection valves available. The tubing loop is neatly integrated into the housing for temperature stability, and can be quickly adjusted by the user to suit individual requirements.