When studying biological cells using optical tweezers, one main issue is the damage caused to the cell by the tool. Giovanni Volpe, University of Gothenburg, has discovered a new type of force that will greatly reduce the amount of light used by optical tweezers - and improve the study of all kinds of cells and particles.
"We call it 'intra-cavity feedback force'. The basic idea is that, depending on where the particle or cell you want to study is, the amount of laser light used to trap it changes automatically. Whenever the particle is in focus, the laser switches off. When the particle tries to escape, the laser switches on again", says Giovanny Volpe, senior lecturer at the Department of Physics, University of Gothenburg.
An optical tweezer is a focused laser beam that can trap particles. Previously, two different types of forces that emerge from this type of tool have been identified: gradient force (which means the particle goes against the intensity of the laser) and scattering force (where the particle is pushed towards the laser).
Giovanni Volpe and his team have discovered a third type of force in this realm, and a new way of constructing optical tweezers. These break-throughs are poised to greatly improve the study of single biological cells.
"With this method, as much as 100 times less light is needed, in some cases, compared to using a traditional optical tweezer," Giovanni Volpe explains. "With less light, you cause less photo damage to the cell you are studying."
This could be useful for studying any cell that is usually suspended in a solution - a blood cell or a yeast cell, for example - that a researcher would want to study over a long period of time.
"One of the main issues when using optical tweezers is that the light raises the temperature of the cell, which is damaging. A rise of 10 degrees might not be tolerable, but the rise of 0,1 degrees might be fine.
So using less light, and therefore limiting the rise in temperature, could make a huge difference. Experiments could be done in a more realistic manner in relation to the cell's natural life cycle," says Giovanni Volpe.
The findings are published in Nature Communications.
Title: "Intracavity optical trapping of microscopic particles in a ring-cavity fiber laser"
Giovanni Volpe | EurekAlert!
Better thermal conductivity by adjusting the arrangement of atoms
19.07.2019 | Universität Basel
Heat transport through single molecules
19.07.2019 | Universität Konstanz
Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.
In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...
Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.
Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...
Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.
Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...
For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.
Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...
An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".
The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...
24.06.2019 | Event News
29.04.2019 | Event News
17.04.2019 | Event News
19.07.2019 | Physics and Astronomy
19.07.2019 | Earth Sciences
19.07.2019 | Physics and Astronomy