Microinjection of Drosophila Nurse Cells: A Method of Intracellular Delivery

- Place a coverslip with dissected egg chambers onto the microscope stage. Locate an egg chamber of the appropriate developmental stage and orientation for microinjection. Mid to late-stage egg chambers have a large visible oocyte yolk, and those in the correct orientation are with their anterior-posterior axis perpendicular to the direction of injection.

Drosophila nerve cells are a group of 15 cells inside the egg chamber responsible for depositing maternally derived nutrients and biomolecules into the developing oocyte. Set up the microinjector system to the appropriate injection and compensation pressure to ensure consistent injection volume and outward flow. Carefully bring a previously loaded capillary needle into the field of view so that the cells and needle are in the same focal plane.

Ensure that there is no air trapped in the tip of the capillary and that there is a continuous flow of the solution. Then adjust the Z-position of the objective to focus on the membrane separating the follicle cells from the nurse cells, insert the needle into a nurse cell and perform the injection.

The following protocol demonstrates microinjecting Drosophila nurse cells with fluorescent ol