Fiber optic sensor probes a cell.A tiny probe, just one-thousandth the diameter of a human hair, now offers a window on the chemistry inside living cells. Raoul Kopelman, a physical chemist at the University of Michigan (body, education) University of Michigan - A large cosmopolitan university in the Midwest USA. Over 50000 students are enrolled at the University of Michigan's three campuses. The students come from 50 states and over 100 foreign countries. in Ann Arbor Ann Arbor, city (1990 pop. 109,592), seat of Washtenaw co., S Mich., on the Huron River; inc. 1851. It is a research and educational center, with a large number of government and industrial research and development firms, many in high-technology fields such as , has made a set of fiber-optic biochemical bi·o·chem·is·try n. 1. The study of the chemical substances and vital processes occurring in living organisms; biological chemistry; physiological chemistry. 2. probes that can detect specific molecular activities occurring in a cell's liquid interior. He fashions a fine tip from the end of an optical fiber, then coats it with aluminum. He then pierces a cell, shines a laser beam through the fiber, and monitors how the light's intensity and wavelength change. These reveal details of the chemistry at work inside the cell. Kopelman reports assaying glucose, oxygen, sodium, calcium, and potassium ions, plus the cell's pH. A probe can detect changes occurring in as little as one-hundredth of a second, permitting him to track chemical processes "in a single cell, as they occur." Equivalent investigations today require slabs of tissue or live animals observed over days or weeks. Kopelman says the probe could measure activity inside live rat embryo cells "without affecting the cells' metabolism or growth." It also could probe the chemistry of poisoning--revealing "drastic chemical changes inside the cell, occurring within seconds, as the embryo is dying." Studied cells hardly notice the probe, since it takes up as little as one hundred-thousandth the volume of a red blood cell red blood cell: see blood. . "It's like a mosquito mosquito (məskē`tō), small, long-legged insect of the order Diptera, the true flies. The females of most species have piercing and sucking mouth parts and apparently they must feed at least once upon mammalian blood before their eggs can bite," Kopelman says. He suspects the probe could prove useful for testing the effects of drugs on particular cells, identifying gene sequences, or checking embryos for birth defects birth defects, abnormalities in physical or mental structure or function that are present at birth. They range from minor to seriously deforming or life-threatening. A major defect of some type occurs in approximately 3% of all births. . |
|
||||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion