Microinjection in C. elegans by direct penetration of elastomeric membranes

Abstract

The nematode worm C. elegans is widely used in basic and translational research. The creation of transgenic strains by injecting DNA constructs into the worms gonad is an essential step in many C. elegans research projects. This paper describes the fabrication and use of a minimalist microfluidic chip for performing microinjections. The worm is immobilized in a tight-fitting microchannel one sidewall of which is a thin elastomeric membrane which the injection pipette penetrates to reach the worm. The pipette is neither broken nor clogged by passing through the membrane, and the membrane reseals when the pipette is withdrawn. Rates of survival and transgenesis are similar to those in the conventional method. Novice users found injections using the device easier to learn than the conventional method. The principle of direct penetration of elastomeric membranes is readily adaptable to microinjections in a wide range of organisms including cells, embryos, and other small animal models. It could therefore lead to a new generation of microinjection systems for basic, translational, and industrial applications.