Protocols for the Manual and Automatic Microinjection of Somatic Cells in Culture and for the Analysis of Microinjected Cells

Abstract

Micromanipulation of living cells was first used in electrophysiology studies during the first half of this century. Reliable techniques for intracellular recording were developed in the late 1940s. Less than one decade later, similar techniques were applied to perform direct transfer of biological material into cells (see Chambers and Chambers 1961). Initially, microinjection was designed for transplantation of mammalian nuclei (Graessmann 1970) and chromosomes (Diacumakos 1973) into recipient cells in culture. Further refinement of materials and instruments, however, permitted intracellular transfer of solutions containing macromolecules of various origins, such as viral RNA (Graessmann and Graessmann 1976; Stacey et al. 1977), purified proteins (Mabuchi and Okuno 1977; Tjian et al. 1978), and viral DNA (Anderson et al. 1980; Capecchi 1980). Likewise, microinjection was used for DNA transfer into fertilized eggs and a cloned gene was soon reported to be expressed in mouse somatic tissues (Gordon et al. 1980). Later, recombinant genes were stably introduced into the mouse germ line (Brinster et al. 1981; Wagner et al. 1981). Since then, microinjection has been used routinely to generate transgenic animals, and applied to a wide variety of studies using living cells, such as gene expression, signal transduction, or cytoskeleton studies.