microinjection

Microinjection refers to the process of using a micro needle to insert substances at a microscopic or borderline macroscopic level into a single living cell. It is a simple mechanical process in which an extremely fine micro needle penetrates the cell membrane and sometimes the nuclear envelope and releases its contents. Microinjection is normally performed under a specialized optical microscope setup called a micromanipulator. The process is frequently used as a vector in genetic engineering and transgenetics to insert genetic material into a single cell. The process of cloning also involves microinjections.
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Mi·cro·in·jec·tion n. Injection of minute amounts of a substance into a microscopic structure, such as a single cell. [more]Microinjection - Community and Resources

a technique by which part of one cell is injected into another cell, as DNA into ova or other cells to create transgenic animals.