A new method of imaging cells is allowing scientists to see tiny structures inside the nucleus of the cell for the first time. The microscopic technique, developed by researchers at Queen Mary University of London in the UK, represents a major advance for cell biologists as it will allow them to investigate structures deep inside the cell.
Recent advances in optical physics have made it possible to use fluorescent microscopy to study complex structures smaller than 200nm, known as super-resolution microscopy. The drawback of such techniques is that they can only produce very clear images of structures that are at the bottom of the cell. Since the nucleus is in the middle of the cell and bacterial and viral infections can happen anywhere in the cell, this technique has considerable limitations for biologists.
These issues have been overcome with the newly developed imaging system, making it possible to image structures, 80nm or less, anywhere in the cell. The Spinning Disk Statistical Imaging (SDSI) system was developed by Dr Neveen Hosny, a bioengineer working with Professor Martin Knight in the School of Engineering and Materials Science and Dr Ann Wheeler, head of imaging at Queen Mary’s Blizard Institute.
Dr Wheeler said: ‘The SDSI produces focused images at high speed because it has a disk with an array of tiny holes in it which remove the out-of-focus light. We have combined this microscope with new fluorescent probes, which switch between a bright and dark state rapidly.
‘With this system, we have been able to visualise chromatin and focal adhesions with a greater degree of detail,’ added Dr Wheeler: ‘It also allows us to look at protein complexes which are smaller than 200nm in the nucleus, which hasn't been done before. We will be continuing to develop the technology to improve the fluorescent probes used for this technique and will also be applying it to cellular processes such as invasion in cancer.’
Professor Knight pointed to other medical applications: ‘We are looking forward to using super resolution microscopy in a wide range of applications from stem cell behaviour, to understanding arthritis, or in the development of nanomedicine.’
