A practical approach for examining the internal structure and operations of a crucial element of living cells has been devised by scientists at the Indian Institute of Technology (IIT) Mandi in partnership with the University of Cincinnati in the United States. In order to investigate the lysosomes’ nano-dimensional characteristics and functions as well as their interactions with mitochondria, another important cell organelle, the researchers used metal nanoclusters in a technique called structured illumination microscopy (SIM).
SIM is based on the sample being excited by a structured pattern of light and the interference patterns being detected by near-infrared spectroscopy. Although SIM is not a unique analytical approach, the inter-institutional work’s use of metal nanoclusters rather than the more conventional lysosomal dyes has considerably improved the method, according to a release from IIT Mandi.
The typical dyes employed for SIM’s lysosomal detection are photobleached over time and sensitive to the medium’s acidity. Instead of lysosomal dyes, the researchers have employed tiny clusters of noble metals like gold and silver called nanoclusters to investigate the internal structure of this organelle using SIM. These clusters are 100,000 times smaller than the width of a single human hair. These nanoclusters exhibited no photo-bleaching issues and were unaffected by the medium’s acidity. According to a statement from IIT Mandi, because these nanoclusters were small enough to reach the cells and even subcellular regions like the lysosome, they can be used to learn how these crucial cellular substructures function.
“We loaded these nanoclusters with a biocompatible protein called bovine serum albumin and used them to follow the dynamics of the lysosomes in brain organoid,” said Aditya Yadav, a research scholar at IIT Mandi, while describing the study. We specifically looked at the manner by which lysosomes recycle damaged mitochondria inside cells. Professor Chayan K Nandi, IIT Mandi, stated that lysosomes are around a micron in size, or a thousandth of a millimetre, with their interior structure being in the order of 200 nanometers (one-thousandth of a micron). Structures of this size cannot be observed in detail using a conventional microscope.
