text-only page produced automatically by LIFT Text
Transcoder Skip all navigation and go to page contentSkip top navigation and go to directorate navigationSkip top navigation and go to page navigation
National Science Foundation
News
design element
News
News From the Field
For the News Media
Special Reports
Research Overviews
NSF-Wide Investments
Speeches & Lectures
NSF Current Newsletter
Multimedia Gallery
News Archive
Press Releases
Media Advisories
News Tips
Press Statements
Speech Archives
Frontiers Archives
 


Frontiers
Life Like You've Never Seen It Before

February 1996

Follow a white blood cell as it mobilizes to attack a foreign invader. A drop of serum, triggering the same response that would occur in an infection, causes the white cell to reorient itself (in the middle frame, where nucleus and pseudopod, or leading edge, are indicated), then elongate in a new direction. When the cell arrives at the source of the stimulus, it will release the toxic eosinophilic granules shown clustered here.

The images in the right column show the calcium ion level in the cell; lighter areas indicate a higher concentration of calcium. Calcium increases when the cell is stimulated and is always highest in the rear of the cell. Scientists know that calcium is essential for the cell's movement in the correct direction, but the method these calcium ions use to steer the cells is still under investigation. The photographs vividly illustrate the power of a new microscopic imaging technique developed with NSF funding.

Photographs on the cover and these two pages illustrate a new microscopic imaging technique with nearly four times the resolution of previous microscopes. The technique, developed by an NSF-funded team of researchers at the University of Massachusetts Medical Center, combines conventional light microscopes, a sensitive high speed camera and sophisticated computer programs. The technique makes it possible to see details of cellular structures that were previously obscured and to follow chemical events at higher speeds. Researchers can watch as these structures go about their functions in living cells-as in the sequence on the cover. Earlier microscopes show sub-cellular particles, but only at lower speed and lower resolution and under such strong light that the cells are damaged or destroyed.

The new technique uses a mathematical algorithm that reassigns unfocused light to its point of origin, eliminating the blurring that occurs in many microscopes. John Cross, NSF program director of biological instrumentation, describes the procedure as similar to what was done to the Hubble Space Telescope to improve its vision.

CENTROSOME


microscopic image; caption below

Credit: Scanalytics and the University of Massachusetts Medical Center

The centrosome is a sub-cellular organelle that is responsible for organizing many of the proteins which enable cells to move and repoduce. This cage-like structure, one micron (.000001 meters) in diameter, was identified using fluorescent dye, which highlights one of the centrosome's critical proteins, pericentrin.

CELL MEMBRANE


microscopic image; caption below

Credit: Scanalytics and the University of Massachusetts Medical Center

When studying muscle cells in organs such as the heart, scientists need to know the exact location of cell mebrane. A robotic vision system helps to define the surface membrane of the cells that have been stained with a fluorescent dye.

NUCLEAR ENVELOPE


microscopic image; caption below

Credit: Scanalytics and the University of Massachusetts Medical Center

When cells replicate, they move genetic information in the form of messenger ribonucleic acid (mRNA) to specialized sites where proteins are made from specific genes. Researchers believe that the two large clusters within the dark circle called the "nuclear envelope" are the spots in the cell nucleus where DNA is transcribed from the gene into mRNA.

TRANSCRIPTION SITE


microscopic image; caption below

Credit: Scanalytics and the University of Massachusetts Medical Center

In this closeup of a transcription site, the bright spots show signals representing mRNA.


Return to February 1996 Frontiers home page   Other Contents of This Issue
Visit Other Frontiers Issues page   Other Frontiers Issues
Visit Other NSF Publications page   Other NSF Publications
Visit Office of Legislative and Public Affairs page   Office of Legislative and Public Affairs

 

Email this pagePrint this page
Back to Top of page