Figure 1.

A, Schematic drawing of the cross section of the capillary gun. B, Photograph of the gun with a head attached, mounted on a micromanipulator, and aimed at a leech embryo. Inset, Close-up view of the leech embryo with a laser spot (red dot); the end of the gun is seen extending from the top right corner. C, Distributions of penetration depths of 1.6 μm gold particles in leech embryos. The particles were shot at He pressures and distances between the nozzle and the embryo of 14.5 psi and 2 mm, respectively (black curve), and of 10 psi and 4 mm, respectively, (gray curve). The distributions were obtained by fixing the tissue and counting particles at different depths under a dark-field microscope, as described in detail by Rinberg et al. (2005).