MICROMACHINED HOLLOW NEEDLE WITH INTEGRATED PRESSURE SENSOR FOR PRECISE, CALIBRATED INJECTION INTO CELLS AND EMBRYOS

摘要

We have developed surface micromachined hollow silicon nitride needles, specifically designed for injection of DNA and proteins into fruit fly embryos. Precisely controlled calibration of the injected volume is possible using an integrated membrane-based pressure sensor with interferometric read out. The membrane can withstand pressures in excess of 3 bar. The excellent mechanical stability of the hollow needle was verified in fruit-fly embryo injection experiments and the injection of water and a solution of GFP (green fluorescent protein) were successfully performed. Flow measurements of air through a needle with channel dimensions: 75 μm x 15 μm x 2.5 μm, resulted in a flow rate of r_(air) = 1.4 nl / (s bar).