To do this step efficiently, first use your fingers, next the joystick, and finally the thimbles and knobs. An optimum angle of the needle to the coverslip is about 40 degrees in our hands. Change the objective to 40x, refocus on the amoeba, and fine tune the position of the tip. After placing the tip a few m m from an amoeba, simultaneously rotate the injector s pressure control knob and the t-direction knob clockwise. When the tip of the needle penetrates into the amoeba, pull it back.
Video showing the injection process is available on request.
Sometimes, cell debris attaches to the needle. To remove the debris, lift the needle to the surface of the medium and tap the microscope stage a few times. If the debris is still attached, using your fingers, flip the tip of the needle up and down several times, passing through the air-medium interface. The surface tension will rid the debris efficiently. Using a rubber bands, we also provide a continuous, low pressure to the injector to prevent possible clogging of the needle.