Cellular microinjection techniques have developed over the last century along with the evolution of other
biological fields. For example, developmental biologists have used a variety of microinjection techniques
to transfer cytoplasm between cells, inject antibodies and peptides, and express foreign genes in specific
tissues to advance their understanding of cell specification and determination. Molecular biologists finely
craft glass microneedles and tools for the manipulation of cells in order to study gene expression and
communication between cells. As these techniques have matured, microinjection has become accessible
and, thus, exploited by a larger segment of the scientific and medical community. As more and more
information is gathered from the various genome projects, demand grows for methods to validate these
new data. Microinjection can help address this need. In particular, microinjection has proven valuable for
the confirmation and extension of in vitro results in an in vivo setting – the living cell. The technique has
also found a home in the clinical setting, most obviously within the community of fertility specialists for in
vitro fertilization methods and for those excited about the possibility of therapeutic cloning