Author Archives: Anthony Hayes

IN FOCUS: Winging it in Paleobiology: Strange tails from a strange time.

Above: Some of the exhibits on display, including the Meganeura model made by the Bioimaging Hub, at ‘The Fossil Swamp’ exhibition at Cardiff Museum.

How do you make a dragon fly (ask it nicely I suppose)? Well, this was the question we were asking ourselves a few weeks ago after an email enquiry from Dr Trevor Bailey of the National Museum of Wales. Trevor is one of the museum’s senior paleontologists and is involved in curating many of the museum’s public exhibitions and programmes involving fossils and prehistoric life (You can read more via his profile page here).

Trevor had contacted us to enquire whether we might be able to help with a forthcoming exhibition at the museum, called ‘The Fossil Swamp‘, by making a scale replica model of an extinct insect species similar in appearance to a modern dragon fly (it’s actually classed as a Griffin fly), but with one big difference (and I mean BIG): its size. How big I hear you say? Well, to give you an idea of its sizeable dimensions, the wingspan of Meganeura was approximately 0.7 metres long (i.e. roughly the same wing span of a large, adult sparrow hawk)! Indeed, this is how the insect came to earn its rather ominous sounding moniker: ‘mega-neura’ means ‘large-nerved’, referring to the network of large veins supporting the insects enormous wings (Brongniart, 1893)

In fact, Meganeura monyii is one of the largest known flying insect species ever to grace planet earth. It lived more than 300 million years ago, in the carboniferous period where the atmospheric oxygen concentration of air was much higher than that of today (around 35% then, instead of 21% now) which, it is thought, allowed the insects of that period to grow to enormous proportions (insects breathe through small holes, or ‘spiracles’ in their body walls connected to branched air tubes called ‘tracheoles’ which convey oxygen to their internal tissues). Furthermore, at the time Meganeura was buzzing about, bugging the primitive lifeforms of the day, there were no other aerial vertebrate predators around (in fact, birds arrived to the table 75 million years later) so it could pretty much act with total impunity!

So Trevor supplied us with a digital model of the insect for 3D printing, together with the desired dimensions, based on recorded fossil evidence (Brongniart, 1893). Interestingly, the digital mesh was actually created as a component of a carboniferous forest simulation  by a colleague of his in Germany  (link here).  In order for us to 3D print Meganeura’s body to scale using our Ultimaker 3 extended 3D printer, we had to fabricate the head and thorax separately to the abdomen and then re-attach these after removal of their supporting scaffolds. We printed these using polylactic acid (PLA) filament at an intermediate print resolution. The first attempt looked okay, but the finished model was rather blocky in appearance, so we smoothed the digital mesh and then reprinted at a higher resolution with much better results.

1-2 digital reconstructions of Meganeura monyii; 3-5 3D prints of the separate body sections; 6 Support scaffolds removed and body sections reunited – note block appearance of model. The digital mesh was filtered and the model reprinted with much better results (see below).

The next challenge was those huge wings. I downloaded .png image files of the venation patterns recorded by Brogniart (1893) here. However they were simply too large to 3D print at the desired thickness (and believe us, we tried) so a different approach was necessary. Each wing was laser printed onto a separate sheet of acetate. These were then cut out and laminated – the composite structure increasing the rigidity of the wing but still allowing realistic flexion. To attach the wings to the thorax, I drilled holes through adjacent thoracic segments and fed lengths of wire through the holes to support the leading edge of each wing pair. The wire was then bonded in place to prevent any lateral displacement.

7 Wing venation pattern after Brogniart (1893) downloaded from the web; 8: wings laser printed to scale on acetate and laminated; 9 laminated wings cut to final shape.

Next up was the paint job, which became a labour of love (and exercise in mindfulness) in my spare time! Now, unfortunately, no one knows what colours or patterns adorned the body surface of Meganeura as the fossil evidence is all black and white. Artist’s impressions are therefore based loosely on modern equivalents (e.g dragonflies, damsel flies etc), or have just been made up to make the insect look as fearsome as possible – it was a carnivorous predator after all! So after a few Google image searches, just to get some ideas, I finally went with a black and yellow/orange colour scheme with iridescent bronze eyes (with artistic input from Trevor and my daughters). I used acrylic paints, purchased cheaply from The Works, which gave good adhesion and cover without the necessity of a primer coat. Fine detail was added under magnified optics.

10 Smoothed model with base coat of acrylic. Wires have been inserted through thoracic segments to support leading edge of wing pairs; 11-13 Model has been painted and the first pair of wings are awaiting attachment.

When the model was fully painted we attached the wings to the wire frames using extra strong clear sellotape before taking it over to Alexandra Gardens, opposite the School of Biosciences, for some wildlife photography, doing our best not to frighten the native fauna (or general public)!

14-15 The finished Meganeura model – a ferocious looking beast!
16-17 …and doing its best to blend in with the local flora!

The model will be on display as part of the Fossil Swamp exhibition in the National Museum of Wales at Cardiff from 18th May, 2019 to 17th May, 2020 along with lots of other amazing artefacts from the carboniferous period. Please go along to visit – it promises to be a fantastic family day out.


Further reading

  • Brongniart (1893) Recherches pour servir á l’histoire des insectes fossiles des temps primaires : procédées d’une étude sur la nervation des ailes des insectes (Research to serve the history of fossil insects of the early ages : preceded by a study on the wing venation of insects).


Digital mesh of Meganeura monyii was taken from the Carboniferous forest simulation, page author and domain holder Heiko Achilles; 3D printing by Dr Pete Watson; Model painting, wing fabrication and finishing by Dr Tony Hayes; Wildlife photography by Marc Isaacs. Blog post by Dr Tony Hayes.

IN FOCUS: Immersive microscopy – 3D visualisation and manipulation of microscopic samples through virtual reality.

Above: The view inside our Oculus Go VR headset: getting some top-spin on some of our 3D pollen grains!

Hands up who’s seen the provocative Stephen Spielberg sci-fi thriller* Minority Report? In the movie, the main protagonist, chief of ‘pre-crime’ John Anderton played by Tom Cruise, investigates a future crime via a cool gesture-based holographic virtual reality (VR) interface. Whilst current VR technology isn’t quite that far into the future, it’s certainly not far off. Indeed, virtual reality is now becoming a reality in microscopy as researchers strive to improve their 3D understanding of complex biological samples. As creator of both the confocal microscope and the head-mounted display, a forerunner of the VR headset, Marvin Minsky would certainly approve of the convergence of these two technologies. The potential is enormous: imagine, for example, being able to take a virtual tour inside a tumour, to climb into an intestinal crypt or to peel apart the posterior parietal cortex – and all without getting your hands dirty!

‘Immersive microscopy’, as it is now known, is an area of imaging in which Zeiss in partnership with software developers arivis are currently leading the field (you can learn more here). To get in on the act, the Bioimaging hub at Cardiff School of Biosciences has been developing a VR application of our own for visualisation and manipulation of volume datasets generated by the hub’s various 3D imaging modalities. We anticipate that this technology will have significant relevance not only to imaging research within the school, but also to teaching and science outreach and engagement.

We’ve been using the affordable Oculus Go VR standalone headset and controller in association with the Unreal 4 games engine to create VR environments allowing interaction with our whole range of surface rendered 3D models. These range from microscopic biological samples imaged by confocal or lightsheet microscopy, such as cells or pollen grains, to large, photo-realistic anatomical models generated via photogrammetry.

As proof of principle we’ve developed a working prototype that allows users to manipulate 3D models of pollen grains in virtual space. You can see this in action in the movie above. We’re planning further developments of the system including new virtual 3D environments, different 3D models and object physics, and features such as interactive sample annotation via pop up GUIs. The great thing about VR of course is that we’re limited only by our imagination. To borrow a quote from John Lennnon, if ‘reality leaves a lot to the imagination’ then VR leaves a lot more!

*we’ll conveniently ignore his more recent VR-themed sci-fi flick ‘Ready Player One’!


Further reading


IN FOCUS: Standard Operation Procedures (SOP) Repository.

Above: A screenshot of the Bioimaging Hub’s SOP repository

If you wasn’t already aware of the Bioimaging Hub’s SOP repository (N.B. there are shortcuts set up on all of the networked PCs within the facility), then please take a look at your earliest convenience. The database was set up as a wiki to provide Hub users with up to date protocols and tutorials for all of our imaging systems, experimental guidelines for sample preparation, health and safety information in a variety of multimedia formats in one convenient and easily accessible location. It’s still  work in progress and we would welcome any feedback on how the resource could be further developed or improved.

AJH 7.1.19

EQUIPMENT: New X-Clarity tissue clearing system.

One of the problems associated with imaging fluorescence in large biological samples is the obscuring effects of light scatter. Traditionally this has meant physically sectioning the material into optically-thin slices in order to visualise microscopic structure.  With the advent of new volumetric imaging techniques, e.g.  lightsheet microscopy, there is increasing demand for procedures that allow deeper interrogation of biological tissues. With this in mind, an innovative clearing system has recently been purchased through generous donations to the European Cancer Stem Cell Research Institute (ECSCRI). The equipment, which will be housed in ECSCRI lab space, allows large, intact histological samples to be rendered transparent for fluorescent labelling and 3D visualisation by confocal and lightsheet microscopy.

The X-Clarity tissue clearing system is designed to simplify, standardise and accelerate tissue clearing using the CLARITY technique (an acronymn for Clear Lipid-exchanged Acrylamide-hydridized Rigid Imaging/Immunostaining/in situ-hybridization-compatible Tissue hYdrogel). In the technique,  preserved tissues are first embedded in a hydrogel support matrix. The lipids are then extracted via electrophoresis to create a stable, optically transparent tissue-hydrogel hybrid that permits immunofluorescent labelling and downstream 3D imaging.

The new equipment and associated reagents will have wide relevance to many areas of research in Cardiff,  including deep visualisation of breast cancer tumours by Professor Matt Smalley’s research group  using  the Bioimaging Hub’s new lightsheet system. You can see a video here that shows the power of the  CLARITY technique for high resolution 3D visualisation  of tissue and organ structure.

Further Reading


EQUIPMENT: Fast module upgrade for the Zeiss LSM880 Airyscan confocal.

Above: Maximum intensity projections of actin stress fibres (red) and microtubules (green) of an endothelial cell imaged on a Zeiss LSM880 Airyscan confocal microscope. Z-stacks were sampled via: A. Conventional confocal optics (5 minutes scan time) B. Airyscan Fast – 0.5x Nyquist sampling (30 seconds scan time) C. Airyscan Fast – 1.5x Nyquist sampling (1 minute scan time) D. Airyscan Fast – 2x Nyquist sampling (5 mins scan time).

Through generous support of Cardiff School of Biosciences, the Bioimaging Research Hub has recently upgraded its Zeiss LSM880 AIryscan confocal system for fast image acquisition via the Zeiss Fast module upgrade. The AIryscan system allows imaging at a resolution  1.7x that of conventional confocal optics (find out more here) and the new fast  upgrade provides a 4x speed enhancement with improved signal to noise ratio. The technique uses  beam shaping optics to elongate the excitation spot along the y axis so that it simultaneously covers four lines in a single scan. This parallelisation approach, whilst increasing acquisition speeds by a factor of four, allows high pixel dwell times to be maintained resulting in high a signal to noise ratio.  You can read more about the technique below or, if you would prefer,  kick back and watch this explanatory webinar courtesy of Zeiss.

Further reading

Huff, J. (2016) The Fast mode for Zeiss LSM880 with AIryscan: high-speed confocal imaging with super-resolution and improved signal to noise. Nature Methods 13: 10.1038/nmeth.f.398.


IN FOCUS: Making your mind up: 3D printing of brains for Cardiff Museum’s Brain Games 2018

Above: Guess which animal species. Some of the 3D printed brains for the Brain Games 2018 event.

How many of you can tell the difference between the brains of, say, a human, a black rhino and a Sloth bear? Nope, me neither, but apparently, when it comes to brains, it’s not just size that counts (see below). This conundrum is one of the many fab activities on offer this weekend at the National Museum of Wales annual Brain Games event funded by the Society for Neuroscience and highlighting the range of brain-related research undertaken at Cardiff University.

In the build up to the event, our very own Pete Watson in collaboration with Emma Lane (PHRMY) has been 3D printing brains from a wide variety of animal species, including human, on the Bioimaging Hub’s Ultimaker 3 extended dual colour 3D printer. However, just to make things a little more challenging, they’ve generated two sets of 3D prints: the first set of brains are anatomically correct scale models, the other set have all been 3D printed at an identical size – and it’s up to you, dear reader, to determine which brain belongs to what animal species.

Above are a small selection of the 3D printed brains that will be on display at the National Museum this Sunday, including a glow in the dark brain from…well, that would be telling wouldn’t it?!


Further information:


IN FOCUS: Virtual microscopy database: an update.

You may remember one of our blogs from 2015 about a virtual histology slidebox  in development by the Bioimaging hub? If not, link here.  Well, I’m very pleased to report that we’ve made considerable progress since then.

The resource has now been moved from its humble beginnings (a Rasberry Pi/raid drive set-up) to a new PC server based within the Bioimaging hub. The database has also been developed significantly through mySQL which allows efficient management of the image metadata via a web interface, allowing the images to be sorted, filtered and navigated online.  

The image collection has also been expanded significantly; thus, in addition to the original histopathology collection (which contained approximately 400 digitised sections of normal and pathological tissues), we now have two new additional sections on cell biology and parasitology.

The cell biology section contains both zoomable/navigable images and interactive 3D models of intracellular structure, including major organelles, cytoplasmic inclusions and cytoskeletal components. These were all generated from confocal fluorescence datasets imaged using our Zeiss LSM880 airyscan confocal system and rendered in 3D via Bitplane Imaris. The parasitology section, meanwhile, contains over 200 new zoomable/navigable  images of various parasitic species,  organised phylogenetically for easy reference and sorting. As before, these images were generated using our Navigator slide scanning system.

So far, the database has been trialled for small group anatomy teaching, as well as for a number of BIOSI practical classes including Research Techniques (#BIT002), Advanced Research Techniques (#BI4002) and the Identifying Organelles (#BI2231) module. It is also utilised extensively for outreach and engagement activities within the Bioimaging hub to showcase our research capabilities.

As the database is a bespoke system that has been developed in house, there are no costly subscriptions involved. We are also uniquely positioned within the Bioimaging hub to expand and develop the database according to the needs of the user.  It therefore has enormous potential as a centralised repository for microscopical image data for teaching, research and outreach/engagement purposes.

We are planning to add additional sections on plant biology and entomology  and we would welcome collaboration with any BIOSI staff who have access to the relevant slide resources and would be happy to  help in curating these collections.

Ultimately, the plan is to find a permanent home for the virtual microscopy database as part of the new e learning and assessment facility (eLEAF) within BIOSI.

Please take a look at the database here: feedback (+/-) would be welcome.

Thanks again to all involved so far.


IN FOCUS: 3D pollen prints not to be sniffed at: printing pollen for the Met office.

Above:  Not to be sneezed at: 3D pollen prints for the Met Office (grass, green; oak, yellow and birch, blue).

Disclaimer: If you suffer from hayfever then please avoid spending too long on this page – it may be detrimental to your health!

I bet you didn’t know that one in five people  suffer from hayfever and that 95% of pollen sufferers are allergic to grass pollen in the UK alone? Well neither did I until I visited the Met Office’s  really informative pollen forecast website. 

It seems that some of the worst offenders are pollen grains from grass, oak and birch which play havoc with the mucous membranes during the pollen season, causing sneezing, nasal congestion, itchy eyes and triggering asthma in susceptible individuals (and to make matters worse,  these conditions are exacerbated  by drinking alcohol – so no respite there!)

Having read some of our previous blogs (here and here), the Met Office recently asked the Bioimaging Hub if we would generate 3D printed models of some of the worse culprits  (shown above) for their outreach & engagement programme to help promote awareness of hayfever. 

The 3D prints were generated from surface-rendered confocal microscope volume datasets with help from BIOSI 3D printing. We’ve used the technique to generate physical models of a variety of microscopic samples ranging in size from subcellular organelles to whole developmental organisms. If you’re interested, then further details of the methodology are available below.


Further reading:

IN FOCUS: Getting to the root of the problem.

Above: ‘Crowning glory’: Webcam shots (1-12) showing stages in the process of 3D printing a giant human molar (left) and the resultant 3D print with support scaffold removed (central and right).

The other day we were presented with a problem: was it possible to generate a 3D model of a human tooth that could be used for dental teaching and outreach purposes? The only thing was, the individual concerned didn’t specify the desired size. With a build volume of 215 x 215 x 300mm and printing resolution of 20-200 microns, our new Ultimaker 3 Extended 3D printer can print BIG, so what better application to put the new instrument through its paces! After a quick search on, we downloaded a stereolithography (.stl) file of a human molar tooth segmented from computed tomography (thanks to fvillena). We decided to print it as big as we could, but using the lowest print resolution and lowest level of infill. The results, shown above, are quite impressive – it took approximately 24 hours to print the tooth (crown-side down, root-side up) and with the support scaffold removed resulted in a 3D model approximately 300mm in height – about the same size as tooth from an adult T-Rex!! I suppose we can now be accused of (wait for it…) getting a bit long in the tooth!


Further reading:

NEWS: Microscope maintenance course: keeping your ‘scope in tip-top condition.

Above: Some of the class microscopes in various states of dismantlement.

It goes without saying, to get the very best out of a microscope you need to know how to optimise and maintain its performance. That said,  you’d be surprised just how many microscopists don’t know how to properly set up and maintain their microscopes.

Recently, we run our first  microscope maintenance course as part of Cardiff University’s Continuous Professional Development (CPD) programme.  We can’t tell you who it was for; but suffice to say, they use microscopes a lot in their work. The two day course covered the basics of light microscopy and the procedures necessary to keep a microscope squeaky- clean and correctly aligned. The practical element of the course saw delegates clean, rebuild and align both upright widefield and stereo-zoom microscopes. 

Pleasingly, the course was well-received with very good to excellent feedback. Thanks to all who participated on the two busy but  enjoyable days. Thanks must also go to our undergrad students for soiling and mis-aligning the microscopes ahead of the course – they did a far better job than we ever could ; )

Further reading: