With his new book just released we thought it would be the perfect opportunity to chat to John and find out more about his career, intentions for writing his book and his thoughts for the future within the field of Optical Microscopy.
First and foremost, congratulations on the publication of your book! What inspired you to write A Practical Guide to Optical Microscopy?
I have always worked across traditional scientific boundaries, using my optical knowledge to help others, in particular in the life sciences, solve very complex problems. In the last few years I had been increasingly struck by the vast number of new microscopy methods that had been developed and realised that frequently users were perhaps not using the most suitable instrument for their particular imaging task. I felt the time was right for a book which provided a broad overview of the current methods available in microscopy, crucially aimed at giving practical advice in the selection and application of the best instrument for a specific task. I also wanted to produce a book which the non-optical expert could read and understand, but which also had the fundamental physics background present for those who were interested.
The book evolved from talks and discussions with microscopy users where I explained, in I hope understandable terms, the basics behind a specific method and why it should be selected for a particular application. Although it is not for me to judge, I have also been told that I could explain complex optical effects and systems in a way that was easy to understand and I hope that this book has achieved this end without abusing the fundamental physics too badly!
What first attracted you to microscopy as an area of study, and why did you decide to specialise in it?
In truth I was always interested in both light and technology. When I grew up I remember taking apart an old pair of binoculars and playing with the prisms with sunlight because the effects were things you could see. This was also the time of the manned moon landings and it was the technical aspects of these historical events that interested me. At University my interest in light and lasers grew and I more or less drifted into optical microscopy with the advent of multiphoton methods where my experience with ultra-short pulse lasers could be put to good use. Optical microscopy is also a good field in which to work if you want to undertake multidisciplinary research as you are working with experts from a wide range of backgrounds and thus always gaining new knowledge in a broad spectrum of research areas.
What have been the biggest developments in the field in the last 15 years?
Probably the highest profile development have been the various methods that have emerged for beating the optical limit set up the wave nature of light, so called Super-Resolution microscopy. The award of the 2014 Nobel prize clearly raised the profile of these methods and they have led to some new insights. In particular when microscopy is applied in the life sciences I believe there are perhaps two equally important advances. Both of these fit with my overall philosophy in optical microscopy which is one wishes to perturb the sample as little as possible and that generally biology is a four-dimensional challenge involving imaging for extended periods of time to really understand what is taking place. Thus, the development of genetically encoded fluorophores (Nobel prize in 2008) has transformed many fields of research in the life sciences.
When such fluorescent markers are linked with modern light sheet methods, so called SPIM, one can then observe samples for extended periods of time. When adaptive optics, pioneered in astronomy, are included in such systems high resolution, high speed and extended imaging at depth in a live sample is possible. It is also interesting here that the original light sheet microscope was invented in 1905 and was also a contributory factor in another Nobel prize, again in chemistry, but the method was not really practicable until more recent advances in camera technology.
What do you predict the field will look like in another 15 years?
I think that the speed of imaging with high resolution will increase and perhaps more significantly there will be an increase in the complexity of the data sets. As well as having, for example, a fluorescent image one will also have chemically specific data, via integrated spectroscopic methods, as well as local environmental data through techniques such as fluorescent lifetime measurements. This will make the data sets even larger and more complex leading to an even greater requirement for advanced computational methods to help make sense of data. In the case of in vivo imaging this will also lead to a reduction of the number of animals used as more information will be possible from a single experiment.
The other area, and I may clearly be biased here, is an increase in the use of light to deliberately alter the sample through methods known as opto-genetics. The ability to rapidly switch on, or off, biological processes is enabling new insights to be gained as the sample can frequently then become its own control experiment.
How has your book addressed these developments?
After the basics of optical microscopy have been covered in the early chapters each of the new methods has been addressed in a dedicated chapter. These also have a number of references to the most recent research and applications of these advances. The use of genetically encoded fluorophores is commented about in many places and again as this is not the core focus of the book links are made to the best sources of information in this field.
I think there are two aspects, which are linked. Firstly, to select the best method for the specific imaging challenge, not just to use the most sophisticated because it is there. Secondly to appreciate that any optical imaging does perturb the sample under observation and that this effect should be reduced through the use of the correct light level for the application and minimising the use of external chemicals to the system, including being aware that fluorescently encoded markers also perturb the system. Finally, to have fun when using optical microscopes and to have an appreciation of exactly how they work!
What has been a career highlight for you?
I hope in the not too distant future it is the success of this book! Up till now the highlight is not directly in the field of optical microscopy but occurred when I was working for Keeler a UK based ophthalmic company. I had developed the first ophthalmic laser using laser diodes and this meant a new treatment could be applied for a disorder in premature babies known as Retinopathy of Prematurity (RoP). I remember taking the system I had conceived, designed and built and it being used on a baby in a London hospital. After the treatment the mother came up and thanked me for the invention and I floated, rather than walked, out of the hospital.
What advice would you give to an aspiring researcher in your field?
Follow areas of research that you think are going to be interesting. In essence back your own judgement and have the confidence to follow this through despite the undoubted rejections you may have for funding applications or publications. At the end of the day choose things that you think you are going to enjoy and have fun doing.