Singh is also working with scientists at the Sandia National Laboratories in Albuquerque on a device known as the Biocavity laser, which detects fluorescence in individual mitochondria. Some proteins in the mitochondria’s energy production machinery glow; when mitochondria malfunction, the glow is affected. “We can detect changes in a single cell,” Singh says. “Most of our success against cancer has been due to early detection, and if our tests become sensitive enough to find one bad mitochondrion, that may help us find cancer very early on.”

If this and other clinical outgrowths of research into the role of mitochondria succeed, they could open a fruitful focus for detecting and treating disease. “Mitochondria are like a bridge connecting two island suburbs—one island represents the many causes of a disease, the other the resulting symptoms,” says Auckland Hospital’s Barry Snow. “Knocking out all the houses on either side”—in other words, relieving all symptoms or eliminating all environmental and genetic causes—“is difficult. Targeting the narrow bridge”—mitochondrial dysfunction, which appears to link causes and symptoms—“is much easier.”

Dossier

1. Power, Sex, Suicide: Mitochondria and the Meaning of Life, by Nick Lane (Oxford University Press, 2005). A tale of mitochondria’s evolution from free-floating, single-celled bacteria to the most important organelles in our bodies.

2. “Powerhouse of Disease,” by Nick Lane, Nature, March 2006. A fascinating summary of the hunt for nuclear genes that encode mitochondrial proteins, detailing the role such genes play in initiating a variety of common diseases.

3. “Mitochondria, Oxidants, and Aging,” by Robert S. Balaban et al., Cell, Feb. 25, 2005. Balaban presents a clear picture of the mitochondrial theory of aging, supported by studies of aging worms, flies and mice.

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