New method for micromanipulation goes into practice

In cell biology and medical research, powerful imaging methods are used to observe and analyze biological processes in cells. The targeted manipulation of cells under controlled conditions is a major challenge in understanding processes and causal relationships. Researchers are therefore dependent on effective tools that enable them to manipulate individual components of a cell in order to explore their effects on intracellular mechanisms and interactions. However, a common problem with conventional methods of cell manipulation is that the sample is disturbed by the manipulation and the results are thus falsified. The new FLUCS method now allows non-invasive manipulation of cells for the first time, for example in developmental biology.

FLUCS is a method of photomanipulation that makes it possible to specifically influence and control movements within cells and embryos with the help of laser beams. The beam selectively induces a thermal field in the cytoplasm. This locally changes the density and viscosity of the liquid medium and causes a flow due to the rapidly moving laser point. In contrast to conventional methods, such as optical tweezers, the biomolecules floating in the cytoplasm are set in motion directly without the need for modification of the sample. They can still interact freely with their environment. The method can be used in particular to clarify important questions about embryonic development. A research team led by Moritz Kreysing from the MPI (now at the Karlsruhe Institute of Technology) was able to generate controlled currents in living worm embryos and transport biomolecules to different parts of the growing embryo. Through the targeted redistribution, they succeeded in examining the importance of the movement of the cytoplasm for the polarization of oocytes and thus the question of which molecule has to go where exactly during development.

A market-ready product

As part of a development cooperation, the FLUCS technology was transferred from the MPI to the company Rapp OptoElectronic. Based on the successful joint development and the license agreement that has now been concluded, Rapp OptoElectronic is offering FLUCS as a market-ready product to researchers and industrial users worldwide. A pilot system is located in the LMF (Light Microscopy Facility) of the MPI-CBG in Dresden. Here, FLUCS is available to interested scientists from inside and outside the Max Planck Society for their research. The device is integrated as an add-on module to high-resolution microscopes via standard interfaces and can thus be used for photo manipulation with little effort.

“FLUCS fills a gap in the previously available micro-manipulation techniques to study the causes and consequences of intracellular movement. Directed liquid flows are induced by moderately warming up the sample with a laser spot. Their path can be easily specified individually using the user-friendly software, for example as a line, circle or free form. In this way, cell components such as organelles, PAR proteins and even chromatin can be moved freely in the cell nucleus without having to hold or fix them,” says Sven Warnck, Managing Director of Rapp OptoElectronic GmbH.

Diverse applications

The possible applications are diverse. In cell biology, artificially generated cytoplasmic currents can be used, for example, to invert PAR proteins and thus influence embryonic development. In medical research, for example, molecular mechanisms and signaling pathways in cells can be better researched and the development of drugs can be supported. In microfluidics, the behavior of liquid quantities in the micro or picoliter range can be examined in more detail with the help of FLUCS, thus supporting new methods of laboratory measurement technology, quality control or food safety.

"We are pleased that the successful cooperation between the MPI for Molecular Cell Biology and Genetics and Rapp OptoElectronic GmbH will bring first-class commercial products to the market that are far superior to the current state of the art. FLUCS makes microscopy interactive and opens up new possibilities for a variety of research areas," says Dr. Bernd Ctortecka, patent and license manager at Max Planck Innovation GmbH, the technology transfer organization of the Max Planck Society.