Scientists can now eavesdrop and listen to the interaction between different cells in the body in an effort to get an insight into activities of living health cells and killer cancerous cells. Using high-power near-infrared laser light, a team of researchers from the University of Hyderabad and the Indian Institute of Science Education and Research, Kolkata, trapped very small particles (microspheres) of polystyrene beads. This, experts said, could find use in probing the interaction between biological cells.
The minute particles, ranging between 1 milli micron and 1,000 milli micron, were trapped in a tiny chamber formed by a cover slip and a glass slide. Prof. S. Dutta Gupta of School of Physics, Univer-sity of Hyderabad, was part of the research team. Dr Ayan Banerjee from the Physical Sciences department of IISER-Kolkata was the lead researcher. Their work was selected as a research highlight by the prestigious science journal, Nature.
“The ring pattern can be useful for studying tiny interaction forces between micro-particles and controllable study of biological cell-to-cell interactions, such as that between cancer cells and natural killer cells,” Dr Banerjee said. “They studied ordered self-assembly by employing a single pure Gaussian beam emitted by a near-infrared laser. They used an inverted microscope to focus the beam onto a sample chamber formed by a cover slip and a glass slide. The sample chamber contained spherical beads of polystyrene dispersed in water,” said the research highlight in Nature.
Slight manipulation of the microscope focus caused spherical aberrations in the cover slip that pushed the beads towards the edge, leading to the formation of well-defined closed ring structures. Switching off the optical trap caused the beads to diffuse away, only to reassemble almost instantaneously in the same ring structure after the trap was switched on again.