Dr. George Palade, the UC San Diego Nobel laureate whose work isolating, imaging and identifying the function of minute organelles within cells prompted the Nobel committee to label him and his co-winners the fathers of cell biology, died Tuesday at his home in Del Mar, Calif., after a long illness. He was 95.
Working in the 1950s and '60s, Palade took advantage of the newly developed techniques of differential centrifugation to separate the intracellular components and electron microscopy to image them. Using those techniques, he identified the function of, among other things, mitochondria, the power plants of the cell, and ribosomes, the protein-making machinery.
For The Record
Los Angeles Times Saturday, October 11, 2008 Home Edition Main News Part A Page 2 National Desk 1 inches; 27 words Type of Material: Correction
George Palade obituary: The obituary of Nobel laureate George Palade in Friday's California section misspelled his wife's last name as Farquher. Her name is Marilyn Gist Farquhar.
"Dr. Palade had a tremendous impact on the course of science, as well as a personal impact on countless colleagues and students who were inspired by his teaching and example," said UCSD Chancellor Marye Anne Fox.
"George Palade was not only one of the leading scientists of his era, but was a pioneer in modern cell biology, using electron microscopy to study and describe subcellular structures for the first time," said Dr. David A. Brenner, vice chancellor for health sciences.
When Palade immigrated to the United States from Romania in 1946, most studies of cellular interiors had been performed with optical microscopes, which magnify objects only about 1,000-fold and thus cannot resolve the finer details of structure.
Electron microscopes, first produced commercially in 1939, could easily exceed the 10,000X magnification required to see the interior of the cell and can now give magnifications of 2 million or more.
But time was required to develop techniques to isolate appropriate specimens and prepare them for the microscope.
Working with Albert Claude at the Rockefeller Institute for Medical Research -- now Rockefeller University -- in New York, Palade began developing ways to separate cellular components. He, George Hogeboom and Walter Schneider developed the widely used sucrose gradient technique in which cells are first homogenized in a blender to break up cellular membranes.
The homogenate was then layered onto the surface of a test tube containing sugar water, with a very high concentration of sucrose at the bottom and steadily decreasing concentrations at higher levels. When the test tube was spun at high speeds in an ultracentrifuge, the heaviest cellular components, such as the nucleus, would sink into the densest layer at the bottom, while lighter components would segregate at different levels, allowing Palade to isolate individual components of the cell.
