Gene delivery by direct injection (microinjection) using a controlled-flow system

INTRODUCTIONThis protocol describes a method for constant-flow microinjection using the Pneumatic PicoPump (World Precision Instruments). This type of system is very simple and can be assembled on a relatively low budget. In this method, a constant flow of sample is delivered from the tip of the pipette, and the amount of sample injected into the cell is determined by how long the pipette remains in the cell. A typical system is composed of a pressure regulator that can be adjusted for two pressures (back pressure and injection pressure), a capillary holder, and a coarse and fine micromanipulator.