Analyzing a Single Mitochondrion
Cells contain many swarming mitochondria - constantly reproducing by division and being culled by recycling mechanisms. These are the cell's power plants, the evolved remnants of symbiotic bacteria that contain their own DNA and toil to turn food chemicals into ATP. Mitochondrial DNA damage is important in aging, but it progresses in ways that are challenging to examine due to the nature of the mitochondrial life cycle. Here, researchers demonstrate a new application of technology that - even though focused on mitochondrial disease - will enable far more detailed research into mitochondrial damage and aging: "The trouble is that it's very difficult to extract single mitochondria from an individual cell. For years, the best technique has been to break open a group of cells and collect the mitochondria from all of them in a kind of soup. As you might guess, it's hard to determine which mitochondria came from what cells - yet that's what we need to know. ... The research team [has] potentially solved this problem by realizing that several devices and techniques can be used together to extract a single mitochondrion from a cell that possesses a genetic mutation. They employed a method previously used to extract single chromosomes from isolated rice cells where a laser pulse makes an incision in a cell's outer membrane. Another laser is used as a 'tweezer' to isolate a mitochondrion, which then can be extracted by a tiny pipette whose tip is less than a micrometer wide. ... This approach allowed the team to place a single mitochondrion into a small test tube, where they could explore the mitochondrion's genetic makeup by conventional means."
Link: http://www.sciencedaily.com/releases/2011/01/110106145303.htm