You’d be forgiven for thinking that a microscope would be essential to explore the intricate 3D structure of a pollen grain. Well, how about climbing on top of it and exploring it by hand instead? Confused? Please read on.

If you’ve visited this site before then, chances are, you’ll be aware that I enjoy ‘noodling around with pollen’ : )  Over the last seven years,  the Bioimaging hub has developed  and refined methodology that permits  3D printing and both virtual and augmented reality (VR and AR, respectively) visualization of microscopic samples such as pollen grains for use in educational and immersive learning experiences. A direct offshoot of this work has been the development of  what is  currently the largest online repository of 3D pollen grain models worldwide.  To date, I have curated over 170 published, DOI-referenced 3D pollen models from over 150 species of plant which can be downloaded free, for non-commercial usage, via  the Bioimaging Hub’s 3D Pollen Library Collection on the NIH3D website.   You can read more about the evolution of this resource in the links below (including a recent article I have written for the Royal Microscopical Society In Focus magazine, December edition – to follow).

Recently, the project took another interesting and unexpected evolutionary turn. I was contacted by Finnish visual artist and film maker, Saara Ekström, who pitched to me an amazing idea for a collaboration: gigantifying some of our 3D pollen models as public art sculptures for an elementary school in Helsinki, Finland. The plan was to cast the sculptures in coloured eco-friendly natural concrete at a range of sizes between 0.7  and 2 metres to create a magical ‘Alice in Wonderland’ outdoor learning environment for the children, helping to raise their awareness of the unseen, natural world and fostering an understanding of ‘one of nature’s smallest and most essential components’. An absolutely wonderful idea! 

As part of the project, a protected piece of old-growth forest, purchased from the Finnish Natural Heritage Foundation, will be presented as a gift to the School, thus preserving something that is vitally important to future generations of children and linking the pollen sculptures to this natural ecosystem. Having kids of my own (and ever mindful of the ongoing environmental crisis) I was delighted to support Saara’s ambitious project.  The thought that pollen grains from flowers in my back garden would be reproduced as two metre concrete megaliths nearly two thousand miles away in Helsinki was also simply irresistible! Stonehenge, nothing ; )

Saara identified four pollen species of  interest from our collection: blue passion flower (Passiflora caerulea); common thyme (Thymus vulgaris); black elderberry (Sambucus nigra) and common ragweed (Ambrosia sp.)  which exhibited strikingly different morphologies and surface ornamentation (see below). Some of the more spiky and ornate pollen grain species (e.g. common daisy, Bellis perennis) in our collection were deliberately avoided since the children would have to be able to climb on them safely without risk of impalement!

So how does one create a gigantic concrete sculpture of a microscopic pollen grain? Well, this was one of the first things I asked Saara, who was more than happy to explain the steps involved. First, our 3D pollen meshes are downloaded from the NIH3D website and scaled up into virtual models of the sculptures using CAD software, taking care to retain as much surface detail as possible (see below). The pollen grain mesh is also truncated in order to form a flat, stable base (we wouldn’t want them to accidentally roll onto someone’s foot, after all!)

The meshes are then used to program a tool that mechanically carves a negative form of the 3D models into large, high density styrofoam blocks to create the complementary halves of the casting moulds, as shown below.

Once the moulds are created, steel reinforcement is incorporated into the cavity to add structural strength to the sculpture. Coloured eco-friendly natural concrete is then cast, using different coloured pigments for each pollen species. Once the concrete has cured, the moulds are removed and (in the words of Saara) ‘Volia, a microscopic pollen grain has grown to nearly monumental proportions!’ 

The concrete sculptures are then hand finished and a coloured protective coating is added before they are moved to their final destination, the Kallio primary school in Helsinki. At the site they are carefully lowered into place by crane. Rubber protective matting is then installed around each sculpture.

As the winters are long and dark in Finland, customised mood lighting will illuminate the sculptures creating a warm and inviting ambience, as depicted in the concept art above. I think it is fair to say that Saara, has done an absolutely monumental job!

The pollen sculptures were commissioned by the City of Helsinki and will be administered by the Helsinki Art Museum who are responsible for all the city’s public art collection.

AJH 25/09/2024

Further reading

• IN FOCUS: Bigging it up: 3D printing to change the shape of microscopy (February, 2016).
• IN FOCUS: Development of a 3D printed pollen reference collection (August, 2016)
• IN FOCUS: 3D Pollen prints not to be sniffed at: printing pollen for the met office (July, 2017).
• IN FOCUS: Immersive Microscopy: 3D visualisation and manipulation of microscopic samples through virtual reality (February, 2019)
• IN FOCUS: Plastic fantastic: making pollen models for the National Botanic Garden of Wales.(October, 2019)
• IN FOCUS: AR Palynology: probing the reality of nature/nature of reality (November, 2022)
• THE 3D POLLEN LIBRARY: from humble beginnings to the largest online collection of morphologically-accurate 3D printable pollen models.
• IN FOCUS: The ‘3D Pollen Library’: An Update.

• Perry, I., Szeto, J-Y., Isaacs, M.D., Gealy, E.C., Rose, R., Scofield, S., Watson, P.D., Hayes, A.J. (2017) Production of 3D printed scale models from microscope volume datasets for use in STEM education. EMS Engineering Science Journal. 1 (1): 002

 

Over the last 12 months I’ve been working closely with biovisualisation specialist Dr Kristen Brown at NIH3D to curate our 3D pollen model resources into a purpose-built 3D collection:  the ‘3D Pollen Library’. This collection is now featured on the NIH3D homepage and, at the time of writing, represents the largest collection of 3D pollen grain models worldwide. To date, it contains over a hundred entries together with taxonomic metadata and links to other well-established online pollen resources – a significant achievement considering its humble beginnings (you can read more about the background work leading up to it here.)

Enormous thanks must go to Kristen and her team who have been incredibly helpful throughout in accommodating my (many) requests regarding the ‘look and feel’ of the curated collection. They have done an absolutely splendid job.

In parallel with the above, I’ve established an ongoing collaboration with Dr Heather Pardoe (senior botanist and chief palynologist at Amgueddfa Cymru, National Museum Wales). This collaboration has allowed us to digitise and 3D model pollen grains and spores from selected plant species in the museum’s extensive archival pollen collection using methodology we’ve developed in-house at the Bioimaging Hub. The 3D pollen models produced via this collaboration will be added to our NIH3D library as a separate pollen sub-collection, as well as being viewable as part of the full collection. It is envisaged that these models will have significant utility as educational tools for teaching and exhibition.

Further reading:

• Perry, I., Szeto, J-Y., Isaacs, M.D., Gealy, E.C., Rose, R., Scofield, S., Watson, P.D., Hayes, A.J. (2017) Production of 3D printed scale models from microscope volume datasets for use in STEM education. EMS Engineering Science Journal. 1 (1): 002
• IN FOCUS: Bigging it up: 3D printing to change the shape of microscopy (February, 2016).
• IN FOCUS: Development of a 3D printed pollen reference collection (August, 2016)
• IN FOCUS: 3D Pollen prints not to be sniffed at: printing pollen for the met office (July, 2017).
• IN FOCUS: Immersive Microscopy: 3D visualisation and manipulation of microscopic samples through virtual reality (February, 2019)
• IN FOCUS: Plastic fantastic: making pollen models for the National Botanic Garden of Wales.(October, 2019)
• IN FOCUS: AR Palynology: probing the reality of nature/nature of reality (November, 2022)
• THE 3D POLLEN LIBRARY: from humble beginnings to the largest online collection of morphologically-accurate 3D printable pollen models.

 

With the dizzying pace of technological innovation and ongoing advances in microscopy and imaging, it is becoming increasingly difficult to keep abreast current developments in the field. With this in mind, we’ve rounded up some essential resources, from basic to advanced, that will keep you informed and updated.

Online magazines & journals:

• Imaging & Microscopy
• InFocus
• International Labmate
• Journal of Microscopy (through Cardiff University)
• Microscopy (previously Journal of Electron Microscopy)
• Microscopy and Analysis (premier free journal in microscopy & imaging)
• Microscopy Today
• Micscape (amateur microscopy)
• Microbehunter (amateur microscopy)
• Nature Methods
• Physicsworld
• The Biomedical Scientist
• The Scientist

Educational portals:

• Leica Science Lab
• Nikon Microscopy U
• Olympus Microscopy Resource Center
• Zeiss Online Campus

AJH

For the time being, use of the Bioimaging Hub is going to be a very different experience for everyone. In drawing up these guidelines we’ve taken a lead from the Welsh Government and have started with a very cautious approach that we’ll constantly review and relax where possible. For now, the guidance may seem quite stringent so please bear with us while we all adapt to this new way of working.

Access is not permitted to the Bioimaging Research Hub without (i) completing a risk assessment form that should cover all planned activities within the facility and (ii) reading all relevant supporting information (see below). A template risk assessment is available through the Bioimaging Hub’s main web pages.

Before completing the risk assessment form, all users must download and read the following documents:

Cardiff University’s COVID-19 secure organisational risk assessment

The Bioimaging Hub’s local COVID-19 security guidelines

DO NOT enter the Bioimaging Research Hub:

• If you are SARS-Cov-2 positive or are displaying symptoms of COVID-19 infection (e.g. persistent coughing, elevated temperature, anosmia, sickness).
• If you have been in a high-risk area or have had recent contact with confirmed SARS-CoV-2 positive individuals within the last 14 days.
• If you have an underlying health condition and are concerned it will put you at greater risk of developing severe COVID-19 symptoms. N.B. essential work can be undertaken by Bioimaging Hub staff at a supported rate if necessary.

COVID Working Regulations within the Bioimaging Research Hub

All users of the facility:

• MUST read the above documentation before entering the Bioimaging Research Hub.
• MUST contact bioimaginghub@cardiff.ac.uk before entering the facility.You are not permitted to simply drop-in unplanned. Drop off/collection of histology samples must be arranged in advance. Researchers must knock before entering histology via E/0.08 and observe all safety directives outlined in this document. Users must complete a histology request form to specify processing preferences in advance of their visit.
• MUST wash their hands upon entering and leaving the facility (hand wash station opposite office area). Multiple gel hand wash dispensers are also available within the microscopy suites.
• MUST wear appropriate personal protective equipment (PPE) within the facility, including a buttoned-up lab coat and gloves (gloves are provided in all microscopy suites). Eye protection is advisable.
• MUST clean the imaging equipment and immediate working area before and after use (cleaning instructions are available at each microscope station; alcohol spray and lab roll have been provided for this purpose).
• MUST observe social distancing (i.e. 2 metres inter-personal space) within the Hub. The main corridor should be used by only one person at a time. While social distancing measures are in place no training is available and technical support will be provided on a remote basis via telephone (main office: 02920876611; shared office: 02922510220; histology: 02920875139).
• MUST NOT enter the staff office area (0.14A) or histology suites (E/0.06-E/0.07). Drop off/collection of histology samples must be arranged in advance (use E/0.08).
• MUST knock before entering any room. All microscopy suites are now single occupancy (i.e. one in, one out with at least 15 mins user-free time between bookings). The microscope booking calendars have been replaced with room booking calendars, as follows: “BIOSI – E/0.03 – Confocal/Lightsheet microscopy”, “BIOSI – E/0.04 – widefield microscopy”, “BIOSI – E/0.05 – spinning disc microscopy”. New booking instructions can be found here.
• MUST set the room occupancy status (vacant/in use) on the door sliders of the microscopy suites before and after use.

FURTHER READING

German BioImaging recommendations for operating Imaging Core Facilities in a research environment during the SARS-CoV-2 pandemic

Leica: How to sanitize a microscope

Olympus: How to clean and sterilize your microscope

Zeiss: Cleaning and disinfecting the microscope and its optical components

With the University (and entire planet) in lockdown due to the ongoing covid 19 pandemic, now seems as good time as any to make you aware of the Bioimaging hub’s ‘rebooted’ YouTube channel, if you was not already aware of it.

A decade is a long time in imaging. Way back in 2009 we set up a YouTube channel to showcase the capability of our new, all-singing, all-dancing Leica SP2 confocal microscope. At the time, we uploaded a collection of short 3D animation sequences that highlighted some of our ongoing research applications. Fast forward eleven years. Whilst many of those early demo videos have been highly viewed (one over 20 thousand times) they’re starting to look rather dated, particularly when compared to the material that we’re now producing using our new confocal and lightsheet systems and 3D analysis software. As I say, a decade is a long time in imaging.

So, with the advent of spring, we thought it was high time we dusted down our YouTube channel and gave it an overhaul. As well as introducing lots of nice new image content from some of our latest 3D imaging systems, we felt that the channel would have a greater sense of purpose if we were to develop it into an educational resource for microscopy and bioimaging, with obvious relevance for remote learning (i.e., perfect in our current circumstances). Consequently, we have started to collate the most useful and relevant of YouTube’s microscopy-related content (webinars, tutorials, demonstrations etc), ranging from the basic principles of light microscopy to cutting-edge fluorescence-based nanoscopy techniques such as FLIM, so that they are all placed under one roof for your convenience : )

One of the things we hoped to provide our userbase was a series of video tutorials for the hub’s many microscope systems. Whilst there’s a great deal of useful training material on YouTube, in the main, it tends to be aimed at many of the high-end, turn-key imaging systems. Furthermore, not all microscopes are created equal, they each have their own peculiarities which reflect their intended function and most ‘evolve’ over time, through upgrades, to accomodate the vagaries of research. So, with this in mind, we have started to create our very own bespoke training videos for each of the hub’s microscope systems (example here).

The new training videos will supplement the standard operating procedures (SOPs) we have written for all of our imaging equipment and should provide an invaluable resource for user training and e-learning. As such, they will be embedded within the appropriate sections of the hub’s SOP repository (read more here). The online video content and their associated SOPs will be viewable at the click of a mouse button via desktop shortcuts on all of our microscope-associated PCs allowing easy access during instrument operation.

If you have time on your hands, then please pop over to YouTube and take a look at how our channel is developing (link here). It’s still work in progress but, as I say, it has the potential to be an extremely useful resource; not only for hub users, but anyone with a passing interest in microscopy and bioimaging. Constructive feedback is welcomed.

AJH.

The Bioimaging Hub’s conventional widefield microscope systems have recently received some performance upgrades. Details of upgrades below:

• Olympus BX61 fully motorised system: Upgraded with new PC (Win 10) and 4K widescreen monitor, Hamamatsu Spark CMOS camera, CellSens Dimensions software and new CoolLED pE300 white LED illumination source.

• Olympus BX40 system: Upgraded with new PC (Win 10) and widescreen HD monitor, Hamamatsu Spark CMOS camera, CellSens Standard software.

• Olympus BX41 Surveyor Slide scanner system: Upgraded with new PC workstation (Win 7) and widescreen HD monitor.

• Olympus BX50 system: Upgraded with new widescreen HD monitor.

• Olympus SZX12 stereo zoom system: Upgraded with new PC (Win 7) and widescreen HD monitor, Orca ER2 firewire camera and HCI image software.

• Meiji macro system: Upgraded with new PC (Win 10) and widescreen HD monitor.

N.B. All of the above systems are now networked via 1GB desktop switches. Up-to-date standard operating procedures and risk assessments for each system are available through the Bioimaging hub’s online SOP repository via their desktop folders (‘Read me before use’). See a member of staff for further details.

AJH

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.

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.

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.

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)!

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.

AJH

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).

Contributors

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.