Until recently, if scientists wanted to study blood cells, algae, or bacteria under the microscope, they had to mount these cells on a substrate such as a glass sheet. And physicists at the universities of Bielefeld and Frankfurt have developed a method to capture biological cells with a laser pointer beam and conduct related studies with very high resolution. In science fiction and movies, this principle is called the “pull beam.” Using this method, physicists have obtained super-resolution images of single bacteria DNA.
The physicist and his colleagues published the results of this research in the latest issue of the journal Nature Communications. One of the problems that researchers face when studying biological cells under the microscope is that any prepared treatment will change the cells. Many bacteria like to swim freely in solution. Blood cells are similar: they flow continuously and quickly, instead of staying on the surface. In fact, if you fix them on a surface, they will change their structure and they will die.
Our new research method allows us to study them at a very high resolution without fixing the cells on the surface of the substrate. These cells are held in one place by an optical traction beam. The principle of this laser pointer beam is very similar to the one seen in the TV series “Star Trek”. He is the head of the Biophotonics Research Group in the Department of Physics. In particular, the sample is not only fixed without a substrate, it can also be turned and rotated. The function of the laser beam is to serve as an extended aid for microscope adjustments in small areas.
Bielefeld physicists further developed the use of super-resolution fluorescence microscopes. This is considered to be a key technology in biology and biomedicine, because it provides a method to study the biological processes of living cells in a high-scale situation. At present, this kind of research can only be realized under the electron microscope. . In order to obtain such a microscope image, the researchers add fluorescent probes to the cells they wish to study, and then these cells are illuminated under the direction of the green laser pointer beam. Then, a sensor can be used to record this fluorescent radiation, so that researchers can even obtain a three-dimensional image of the cell.
In their new method, the Bielefeld researchers used a second laser beam as an optical trap, allowing the cells to float under the microscope and move as the researchers wanted. “The laser beam is very dense, but it is invisible to the naked eye because it uses infrared light. He is a member of the biophotonics research team.” When the laser pointer beam is pointed at a cell.
Place it at the focal Laser Engraver of the beam and force will be generated in the cell. Using their new method, physicists at Bielefeld University have successfully achieved the holding and rotating state of the cell, and in such a way that they can obtain images of the cell from several sides. Due to the rotation, researchers can obtain a three-dimensional structure of DNA with a resolution of approximately 0.0001 mm.
Professor Huser and his team hope to further modify this research method, which will allow them to observe the interactions between living cells. Then, they will be able to study, for example, how bacteria penetrate cells and other processes. In order to develop new methods, scientists from Lefeld University collaborated with professors and researchers from Wolfgang Goethe University Frankfurt.