The value of an older microscope

blog
Article image: 

They say that many things improve with age: wine, cheese, art and some cars! But I don’t typically hear this said about microscopes and I’ve previously talked about the importance of funding capital equipment to replace older workhorse instruments once they’ve seen better days. My previous post was about desktop SEMs and how they offer an affordable access to EM, but today I’m going to share with you something that I’ve been lucky enough to realise recently about older microscopes.

For the past four years I’ve been responsible for a FIB-SEM, which is not top-of-the-line, but does allow me to work with a range of people and sample types from a range of disciplines (something I’m very thankful for). One of the upsides to the microscope not being top-of-the line is the slightly more relaxed approach to trying new things, with unusual samples or new approaches to obtain answers to research questions. Many of us are familiar with making changes to imaging parameters, protocols or sample preparation and in some cases the hardware we use, so this isn’t particularly groundbreaking, but hear me out!

As stated before, having an older microscope is often seen as a disadvantage, but it can mean that you are freer to modify the system. It is in this area that I firmly believe that we drive forward the boundaries of our disciplines and the practices in microscopy and it is essential to the establishment of new hardware, techniques and the advance of the science that it underpins. Some of the most exciting recent developments have been where people have tried to combine two techniques such as scanning EM and Raman microscopy, sometimes known as ‘RISE’, and include systems from Renishaw or Nanounity or scanning EM with fluorescence from Delmic. Other recent combo-instruments include the iCorr from FEI. I’d imagine that during the development of these now commercial solutions someone started by modifying an SEM or TEM and I’d be willing to bet it was an older model rather than new one.

The typical setup in the SECOM product that combines SEM and fluorescence microscopes, courtesy of Delmic.

Another thing that having an older instrument has shown me is to use the limitations as an inspiration, to problem-solve and to look for alternatives to buying a new instrument, which, let’s face it, isn’t usually a real option. Let me give you an example of what I mean from personal experience. Due to limited resolution (I have a non-field-emission source), sample type and an older style detector, I was unable to make out features within biological samples when performing cryo-FIB-SEM. Although initially frustrated, a colleague of mine asked whether we might be able to use the milling artefacts that were visible (often referred to a curtaining to those in the field) to inform us about the resistance to milling and link them to structures present. Whilst not the same as viewing the actual structure it was an interesting idea and attracted interest from a range of international conferences (EMC2012 and MC2013) and led to an article in Imaging and Microscopy .

Human osteoblast cells showing different susceptibility to successive sweeps of the ion beam. From C Parmenter et al. Courtesy of Imaging and Microscopy 2:34, 2013.

Other ‘pet’ projects have required the manufacture of new stages or addition of sensors or gadgets to vacuum ports. I think that this part of the experience of trying or designing something new is the most exciting (and sometimes maddening). I’m fortunate to have a support workshop who offer engineering, vacuum and electronics support, which makes designing and manufacturing modifications to kit more straightforward. However, it is not without risk and we are sometimes pushing the boundaries of what others might call ‘safe for the instrument’, which is all the more reason to not use a flagship instrument, although I know there are a few people who do.

The benefits can be substantial to researchers, students and academics and come in the form of unique sample analysis, invitations to present at conferences or commercial interest from manufacturers to support the work. This may come in the form of offers to support the work financially, instrument support/maintenance, loan equipment or IP/patents if the idea is a tool or technology of commercial potential.

I think the last point (interest from companies) can be especially exciting for students, particularly if they have an interest in the technique development. The exposure to a world beyond the sphere of academia can be a welcome change and a valuable addition to their training. A few years back I had a conversation with a professor who admitted he'd been working on a development project for nearly twenty years and that the focus of his PhD had been to design a new detector for an SEM. "The project started by ripping out the existing detector and replacing it with my designs," he added, "but most people wouldn't ever consider doing that nowadays." Whilst I'm not advocating quite these steps (don't blame me if your students dismantle something by tomorrow morning) I think it shows that we have a history in microscopy of being innovative and we shouldn't lose that.

So, in conclusion what am I saying? I suppose this is an encouragement to those with ideas and to departments and schools with older instruments. Allow technicians, post-docs and students to play with microscopes to explore additional functionality that could be designed in or limitations that could be perceived and used as an advantage. The other option that I haven’t really touched on is for universities to use older kit for undergraduate and postgraduate teaching. I know there are many who already do this, but have you ever considered opening this up to local sixth form or further education colleges? There may even be some STEM funding attached for this sort of outreach and it could attract prospective students. Finally, I suppose there is always the option to donate the microscope to an enthusiasts club or museum or sell it on Ebay! As usual, I’d be happy to hear your comments.

Website developed by S8080 Digital Media