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As you can see from the video above, I have been working hard with putting together a few exhibitions recently. As we specialise in 3D electron microscopy I had the idea that it would be a good to 3D print our data and take the models to groups of people who cannot usually access microscopy, those who are visually impaired or blind. I have had a great team working with me and you can see the results in these videos. It is amazing when children and adults respond so enthusiastically to what you are doing. While all the work has been exhausting, I think it was worth it in the end.
The 3 prize winners achieved a breakthrough in light microscopy by going beyond the theoretical resolution limit determined by Abbe's law, which states that the resolution that can be achieved is half the wavelength of the electromagnetic radiation used to image it. With the wavelength of visible light being between 380 and 750 µm and ultraviolet extending this to approximately 200 µm, the theoretical limit is 200 nm. Viruses and molecules are frequently much smaller than this and the main way to image them previously was using electron microscopy.
However, the nobel prize winners have been able to turn physics on its head by using molecules that fluoresce, bring molecular resolution imaging to light microscopy. Their work has turned microscopy around. Electron microscopes are restricted to looking at non-living samples due to the harsh vacuum environment and intense electron beam within the microscope. Biological samples have to be carefully prepared for electron microscopy using methods that can take days or weeks. The advantage light microscopy has is that it can look at living samples, allowing scientists to observe dynamic events as they happen. With this now being extended to the molecular level, the opportunities to obtain information about how our cells work has been expanded to unprecedented levels. Congrats to the nobel prize winners, Eric Betzig, Stefan Hell and William Moerner!
Take 1 smartphone or tablet with a front facing camera.
Place a drop of water onto the camera lens. Make it as spherical as possible.
Position the object you want to image over the top and adjust height to focus.
Take the image.
For other easy ideas to turn your phone into a microscope, why not come to the Ashmolean museum in Oxford, UK. just one of the many events going on as part of the Oxford Brookes university 150th anniversary celebrations. http://www.brookes.ac.uk/150-years/live-friday/
I have launched a new project featuring jewellery created from the shapes of human chromosomes. Each item of jewellery is 3D printed. i am very excited about this project, please take a look and let me know what you think!
Personally, I am not sure how much of good idea building your own SEM is, especially as only glass is used to house the vacuum and electron beam. Electron microscopes generate a lot of X-rays and glass is not a good enough deflector. Still, it IS impressive. i am not clear what was being shown with the image but look forward to seeing a bit more about this project. :)
The calendar is now available and can be ordered through this site from the calendar link in the menu. I also have just opened an Etsy shop for prints of my images. Please get in contact if there any prints I have not yet put up (it takes a surprising amount of time to list things properly)
I have just launched my first kickstarter project! If you are interested in having some of my images on a calendar for 2014 please support it!
I am very excited and nervous at the same time!
Ok, so this isn't a new microscopy technique. However, electron microscopy is used to image these beautiful and tiny artificial flowers. They are created by combining two materials and then altering the conditions. What is cool is that the conditions for certain shapes using these materials has now been fairly well determined, which means we can build designs such as flowers by altering the conditions in a determined manner. This will enable scientists to grow materials to set specifications and shapes at a very small scale.
Why are the biological preparation procedures for electron microscopy so complex and technical? Why can we not just put a sample under the microscope?
The image above shows why. While it looks pretty, the ripples that you see are not a natural feature of the bee's compound eye (the underlying hexagonal structures in the image). The ripples are caused by putting the sample into a vacuum prior to drying it sufficiently and are the result of water evaporating from the surface, causing significant damage to the surface.
All biological specimen preparation for microscopy aims to preserve the sample as close to the living state as possible. With light microscopy, imaging live, dynamic samples is achievable and routinely used. This is not possible with electron microscopy due to the necessity for high* vacuum requirements.
As such, samples must be prepared to withstand the vacuum conditions. This requires removing or stabilising all water in the sample. However, dehydration has the effect of coagulating proteins, molecules and other cellular and extracellular components, changing their arrangement and structure. Prior to dehydration, fixation is applied.
Physical fixation can be applied in the form of rapidly freezing the sample, which can then be imaged in its frozen state with specialised cryo-microscopes. Alternatively, the sample can be dehydrated at -90 degrees centigrade and then brought back to room temperature once all the water has been removed.
Chemical fixation involves the use of chemicals that form bonds between biological structures, preventing their movement when the water is extracted.
The samples are often embedded in a hard resin and sectioned (50-200 nm thick) for transmission electron microscopy or dried for scanning electron microscopy.
The image shown is a false colour scanning electron micrograph of artefacts produced as a result of inadequate dehydration and drying. The micrograph was taken by myself and the false colour applied later. These artefacts are attractive but obscure the biological tissue underneath, which may lead to incorrect conclusions about the structures being studied.
*High vacuum is require in most cases, exceptions being variable pressure/environmental scanning electron microscopes that can work at low vacuum with some cost to resolution.
Biological electron microscopist working at Oxford Brookes University.