Microinjection

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Microinjection refers to the process of using a glass micropipette to insert substances at a microscopic or borderline macroscopic level into a single living cell. It is a simple mechanical process in which a needle roughly 0.5 to 5 micrometers in diameter penetrates the cell membrane and/or the nuclear envelope. The desired contents are then injected into the desired sub-cellular compartment and the needle is removed. 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. Microinjection can also be used in the cloning of organisms, and in the study of cell biology and viruses. Microcapillary and microscopic devices are used to deliver DNA into a protoplast.

[edit] Examples

• One can create simple transgenic organisms by injecting genes into the testicle of a nematode at a point where the cells that will become its sperm are undergoing meiosis. Since the developing gametes share a common cytoplasm, all of the nematode's gametes will carry a foreign gene as the result of a single injection.
• Microinjection is used as a vector in transgenic plant production.
• Microinjection of genes into fertilized eggs is a common vector used in the production of higher forms of transgenic animals.
• Microinjection of a gene knockdown reagent such as a morpholino oligo into eggs or early zygotes is commonly used to probe the function of a gene during development of embryos.

[edit] Sources

http://opbs.okstate.edu/~melcher/MG/MGW4/MG433.html

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