Measuring cells
For the first time, researchers have developed a scale for measuring cells. It allows the weight of individual living cell to determine quickly and accurately. This invention has also caused significant interest both in and outside the field of biology.
Researchers from ETH said, from earthworms and flowers to human beings, we made up of cells. They have already discovered many of their secrets, but until now, it has not been possible to measure the weight of living cells and how it changes in real time, as no suitable method of measurement has existed.
Researchers developed a novel cell scale that measure the mass of living cells within a very short time, but also monitors weight changes over time.
Weighing arm
The cell weighed under controlled conditions in a cell culture chamber. The weighing arm is lowered to the floor of the chamber, where it nudges and picks up a cell. The cell hangs on the underside of a tiny cantilever for the measurements, says, doctoral student Gotthold Fläschner.
The microscopic cantilever induced to oscillate slightly. A second infrared laser measures the oscillations at the other end, where the cell hangs first without and then with the cell. “The cell’s mass can calculate from the difference between the two oscillations,” explains David Martínez-Martín, main inventor of the cell scale.
The computer screen shows the changing weight as a curve. As the measuring apparatus mounted directly on the object plate of a high-performance fluorescence microscope, internal processes in the cell can also observed and filmed while measurements take place.
This allows researchers to track how the weight changes during the cell cycle and cell division. The influence various substances have on the cell’s mass, and what happens when it infect a virus.
“We established that the weight of living cells fluctuates continuously by about one to four percent as they regulate their total weight,” says Martínez-Martín.
However, the biophysicists could prove that cells only stop these second-by-second fluctuations upon dying.
More information: [nanosurf]
