Development of targeted STORM for super resolution imaging of biological samples

Significance 

Microscopes are useful tools in the study of biological systems. They employ the use of optical systems principle for viewing the various specimen under investigation. To date, considerable efforts have been initiated to improve the workability of such optical system devices geared towards enhancing resolution, reducing imaging time and increasing their efficiency. As a result, methods such as stimulated emission depletion microscopy (STED) and localized microscopy among several others have been developed. They have resulted in significant improvements that have for example enabled determination of a nanoscale biological structures.

However, most of these microscopy techniques are faced with various challenges. For instance, it is difficult to image a live cell using the localized microscopy (LM) technique because it requires a high amount of optical power that results in cells photo-damage. It also affects its resolution which also depends on the photo-toxicity. To reduce a large amount of power required during the LM microscopy experiments, a good practice would be to identify and locally image the region of interests by using super-resolution method. It means that the resulting surrounding areas will be left unperturbed, thus calling for a proper and efficient illumination control system for the imaging platform.

Although several illumination control techniques are available, the most prevalent one is the spatial light modulator (SLM). SLMs devices can be further classified into liquid crystal based for phase modulation and digital mirror device (DMD) for on and off modulation.

A group of researchers at University of Sheffield in the United Kingdom: PhD student, Liyana Valiya Peedikakkal and Dr. Ashley Cadby from the Department of Physics and Astronomy in collaboration with Victoria Steventon and Professor Andrew Furley from the Department of Biomedical Sciences demonstrated a digital mirror device based simple illumination system for the localized microscopy and in particular stochastic optical reconstruction microscopy (STORM). The system was used to deliver high power densities to the identified specific imaging areas of the plane sample. Their research work is currently published in the research journal, Optics Communications.

The authors observed that the developed targeted STORM was capable of imaging a labeled cell area of a selected area without causing any photo-damage to the surrounding areas of the samples.

The application of DMD to STORM technology enables the users to select an area of interest within the field of view thereby isolating the other areas without any damages to the cells through the increased illumination powers. It is also suitable for conserving time as the isolated samples can be studied at convenient times. The choice of DMD in controlling power delivered to a particular sample was due to its high speed, large spectral range, and high contrast ratio. The system can also incorporate the use of Fourier ring correlation to measure the resolution of the image and stop when the limit is reached. Although the authors did not establish the relationship between the super-resolution radial fluctuations (SRRF) resolutions, they, however, pointed out that it depends on the power densities and hence are optimistic that it will enable sacrificial of imaging resolution with power.

Development of targeted STORM for super resolution imaging of biological samples using digital micro-mirror device. Advances in Engineering

About the author

Liyana Valiya Peedikakkal, is currently a PhD student in the Department of Physics and Astronomy at the University of Sheffield. Liyana is a recipient of Global Strategic Alliance (GSA) scholarship funded by University of Sheffield through Imagine:Imagine Life. She is a highly motivated and innovative biophysicist with a passion for research. Her long term goal is an active academic career in an institute which can provide cutting edge research facilities with an option for collective, creative entrepreneurship as a team with colleagues contributing to research and development in biophysics.

Liyana currently is the first author in 5 peer reviewed journal papers and has 8 international presentations to her credit. During her PhD, she visited Prof. Suckjoon Jun’s lab in University of California, San Diego (UCSD) and developed a targeted illumination system to selectively illuminate bacteria of interest in a mother machine device.

Liyana is currently working on building a novel illumination/detection system based on Digital Micromirror Device to implement various super resolution imaging modalities in one single setup. She is always very keen to implement the technology she builds to answer various biological questions and pushing the limit to understand life in the nanoscopic world

About the author

Prof. Andrew Furley
I studied Biological Sciences at Edinburgh University specialising in Molecular Biology for my Honours degree. After spending a year in the biotech industry at Biogen S.A. in Geneva, I returned to London to ICRF (Cancer Research UK) where I earned a Ph.D. in Leukemia Biology from University College London. From there I moved to Columbia University in New York where the focus of my post-doctoral work, supported by fellowships from the Jane Coffin Childs Memorial Fund and the Howard Hughes Medical Institute, moved from immunology to developmental neurobiology.

I subsequently returned to the UK, to the MRC’s National Institute for Medical Research at Mill Hill, before taking up a permanent position in the department of Biomedical Science at the University of Sheffield, where I am now Professor of Developmental Neuroscience.

My research is currently focused on the role of neural adhesion molecules in intracellular trafficking as this relates to signalling in neural stem cells and brain tumours.

About the author

Dr. Ashley CadbyI studied for a Ph.D in soft matter physics at the University of Sheffield in the UK. I moved to the University of California Los Angeles to work at the California nano-systems institute where I studied the confinement of conjugated polymers in nano-porous silica. I returned to Sheffield to take up an EPSRC advanced research fellowship, here I developed various scanning near field microscopy modalities. The development of these imaging techniques led to the development of high-resolution microscopes for biological imaging. This has become the main focus of my research and has allowed me to be a visiting professor as UCSB and UCSD and work closely with a number of imaging technology companies.

 

Reference

Valiya Peedikakkal, L., Steventon, V., Furley, A., & Cadby, A. (2017). Development of targeted STORM for super resolution imaging of biological samples using digital micro-mirror device. Optics Communications, 404, 18-22.

Go To Optics Communications

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