- Proteins and Peptides
- Lysates and Cell Lines
I’m Derek Davies, and this is why I teach flow cytometry.
Derek Davies has been a leader in flow cytometry for over 30 years. He directed the Flow Cytometry Facility at what was the Imperial Cancer Research Fund in central London. This post entailed providing a service to the Research Laboratories. Later, he became the head of the facility at the Francis Crick Institute in London, UK. Derek has organized and taught several flow cytometry training courses in the UK and beyond. He has been a chair of the flow cytometry section of the Royal Microscopical Society, chair of flowcytometryUK and has served on the council for the International Society for the Advancement of Cytometry. More recently, he has focused on developing interactive and hands-on flow cytometry training courses at the Babraham Institute Cambridge and the Royal Microscopical Society in York, a role which allows him to apply his years of experience in the field to help guide newcomers through the sometimes-challenging world of flow cytometry.
Can you tell us a bit more about your background and experiences in managing shared cytometry resource facilities in London?
My first experience with cytometry was using a microdensitometer to measure the DNA content in cervical cells in smears. This was a slow process, so when I was introduced to flow cytometry in 1985 my life was transformed! I was involved with an MRC-funded project to look at the feasibility of using flow cytometry as a pre-screening technique, but at the same time I realized the potential of the technology. In 1990, I moved into the Flow Cytometry Facility at what was the Imperial Cancer Research Fund in central London. This post entailed providing a service to the Research Laboratories. In 1996, I became the Head of that facility and was instrumental in growing it from a small service Lab to a much larger facility that, as well as providing a service for analytical cytometry and cell sorting, was also involved in training and able to develop methods specially around cell proliferation and cell death. In 2002, the ICRF became Cancer Research UK’s London Research Institute (LRI) and the Lab continued to grow. In 2015, the LRI merged with the National Institute for Medical Research and I oversaw the merger of two large core facilities, which now houses nearly 30 cytometers and has a staff of 12.
Could you elaborate on the most significant changes that you have seen in flow cytometry over the last three decades?
Although the basics of flow haven’t changed too much, the components we use have. We have seen a much wider variety of fluorochromes being used – flow isn’t just about phenotyping – and in order to use these, the lasers we use have become more versatile (different excitation wavelengths) and more affordable (and smaller!). The major challenge we now face is that to efficiently and effectively analyze data where we have used 10/20/30 fluorochromes, we need to alter our way of thinking.
Which new advances in flow cytometry technology are you or have you been most excited about?
Anything that expands what we can do. We use only one of a whole series of single cell technologies, each of which can supply us with some unique perspective on the cells under study. We are now less limited by the slight downsides of flow - we use a zero-resolution technique so there is no morphological information, but we now have imaging flow cytometry. The problems with needing more targets have been addressed by mass cytometry. Each new technology gives us a little more edge and capability.
Can you elaborate on your new role as the Science Technology Platform Training Lead at the Francis Crick Institute? What do you most enjoy about the position, and being at this unique research institute?
The Francis Crick Institute was established to be a flagship for UK science. We hope to be able to provide the best support and collaborative environment for our Group Leaders. At the same time, a great deal of experience and expertise is embedded into the Science Technology Platforms-STPs (our phrase for core facilities). I hope to be able to use that to show we can provide additional capability training in high-end technologies. This is both internally and externally facing. This is a new and perhaps unique post that will enable me to help the Crick provide high quality training; this will be by establishing a network of experts who can all bring their talents to help raise the bar of scientific excellence in the STPs.
At the Francis Crick Institute, what are some interesting current trends in cytometry usage (whether flow, mass cytometry, or imaging mass cytometry)?
I have always tried to be proactive in provision of equipment to the users of the facility. So, over the years, we have been early adopters of a lot of technology. At the same time, we also have to show that any new technology adds value and reduces the time to results. So, we were one of the first UK sites to adopt the first high speed cell sorters. More recently, we have added imaging flow and mass cytometry to our portfolio. There is now much more of an overlap between STPs as many users will take sorted cells, for example, for sequencing, or take an imaging experiment and want to look at more parameters. Imaging cytometry is taking more of a foothold in our workflows at the moment.
What new areas of research do you forecast flow cytometry becoming or remaining a method of choice?
I don’t think cell sorting will be going away anytime soon. Almost always, cells identified by phenotype will need to be isolated to examine their true functional characteristics. However, we need to ensure that the equipment we use is fit for purpose regarding the end users’ applications. There are still some areas of flow – spectral imaging, fluorescence polarization, pulse shape analysis for example that are under-utilized. Maybe we need to re-employ the physicists and optical engineers that were instrumental in the early days of flow!
What are your training recommendations for researchers to ensure an efficient introduction to this challenging application?
All training should be offered in several flavors and researchers should be trained at an appropriate pace. A robust triage system for new users will ensure that training can be tailored for each one. But in all cases, understanding the basics is vital. It is very easy to get data out of a flow cytometer but knowing that the data has been correctly acquired can be a long process. This starts at the experimental questions stage as that will determine what training will be given and when. We are very keen here at the Crick to train all users to do their own cytometry; it is a great transferable skill and by giving users the understanding of the tools they are using, they will be producing better and more reproducible data.
What is your advice to researchers at the time of preparing their flow data for publication? Are there specific guidelines to follow?
There are some guidelines. ISAC (the International Society for the Advancement of Cytometry) published these some time ago (Lee et al., Cytometry A. 2008 73(10): 926-30) and the Nature Publishing group also has some. I would ask all researchers to go and see their flow core at the outset of their experiments, as thinking about how data will be presented at the outset will often give some clarity in experimental design. Or speak to me or my team!
You have been an integral part of the London Cytometry Club and there was a 30-year celebration at the Crick. What makes this community so special and long-lasting?
I was there at the inaugural London Flow Club meeting in 1998 and the Club is still going strong. The Flow cytometry community in London is a great support and self-help network. By knowing who has which equipment and which skills, those of us in cores are better able to help users. Of course, everyone is also very friendly and open, and I think it’s the welcoming nature that has helped the longevity of the Club!
If you were stranded on a desert island, which records, books or luxury item would you bring with you, and why?