Cancer Research UK on Google+ Cancer Research UK on Facebook Cancer Research UK on Twitter
Skip to main content
Donate

Let's beat cancer sooner

A breast cancer cell on the cover of the journal Nature

An image of a breast cell on the cover of Nature (used with permission)

“The large blue alien blob crawls across the page. Tentacles shoot out from its body, attaching to anything in its reach…”

It sounds like a scene from a science-fiction movie, but such sights are commonplace to the staff of Cancer Research UK’s London Research Institute (LRI) Electron Microscopy Unit. In this case, the blue blob is a breast cancer cell, featured on the cover of one of the scientific community’s glossiest “glamour magazines”, the journal Nature.

The Electron Microscopy Unit (EMU) spend their days in windowless basement rooms in the LRI, taking pictures of the inner workings of cancer cells and their healthy counterparts. They provide detailed magnified imagery of research specimens allowing our scientists to see what is happening inside and on the surface of cells.

Through their images, they capture life happening on a microscopic scale, down to the level of specific protein molecules or strands of DNA. That’s a vital service for the charity’s researchers.

For example, the breast cancer cell image on the front cover of Nature was taken as part of a study investigating the genes and proteins involved in cancer. Images like this provide a snapshot of what’s taking place within and on the outside of the cell – giving researchers vital clues as to how the cell’s behaving.

We’ve put together a little slide-show of images from the EMU team, set to music.

Capturing such detailed images is a long process, with individual projects taking anything from 6 months to a year to complete, depending on the complexity of the research. And it takes a lot of effort to photograph a cell. First, you need the right equipment…

What’s an electron microscope?
If you looked down the most powerful light microscope in the world, you’d be able to distinguish individual objects that are around 200 nanometres apart – roughly 1/500 the width of a human hair. But objects closer together than that would just merge into one.  This is because the wavelength of visible light is longer than 200 nanometres.

But electron microscopes use beams of electrons, instead of light. The wavelength of these electron beams is much shorter, allowing scientists to see structures as small as 1 nanometre (1 millionth of a millimetre).

There are two types of electron microscopes, creating different types of images for different purposes.  Transmission electron microscopes (TEM) fire beams of electrons straight through prepared samples of cells, picking up fine details of the tiny structures within.  This technique allows scientists to see what’s going on deep within a cell – effectively a “molecule’s eye view”.

Scanning electron microscopy (SEM) is slightly different. Instead of firing beams straight through a sample, the beams are angled so they bounce off the cell surface, providing detailed three-dimensional images.  The image of the breast cancer cell from the Nature cover was taken using this technique.

Preparing samples for SEM
It’s not as simple as just sticking a few cells under a lens. Samples of cells need to be carefully processed to preserve the tiny structures within them, to make sure we see a realistic view of what’s there. And cells are viewed under a vacuum inside the electron microscope (unlike light, electron beams can’t travel well through air). Before this can be done, the water in the cell must be removed, otherwise the vacuum would cause it to explode.

The EMU team preserve samples of cancer cells (or healthy cells) using chemicals or by freezing – a process known as ‘fixation’. For anyone who studied chemistry at school, some of the ingredients used may sound familiar. Acetone (the same chemical used in nail varnish remover) or ethanol (pure alcohol) are used to dehydrate the cells until all the water is removed whilst keeping the cell structures in place.

The alcohol is then removed by placing the cell into a pressure chamber called a Critical Point Dryer. The chamber is filled with liquid carbon dioxide, which pushes out the ethanol. A bit of heat and pressure then turns the carbon dioxide into a gas, leaving a perfectly dry and beautifully preserved specimen.

The sample is then coated with a very fine layer of platinum to prevent the image from becoming distorted when the cell is bombarded by electron beams.

The art of electron microscopy
Electron micrographs are initially black and white – the images you see in the media are creatively coloured after being taken. The EMU team use Adobe Photoshop to add colours and visually enhance their images. But this is only for illustrative purposes and isn’t used for scientific research images.

Pictures from the EMU are submitted to three photo-libraries, and turn up all over the world. As well as Cancer Research UK’s own photo library, images are sent to Wellcome Images and Visuals Unlimited. So next time you see an impressive picture of a cell crawling across the page, check the picture credit. You may be looking at the work of our EMU team.

Kat

With thanks to Frank Dias, Cancer Research UK Senior Intranet editor; Lucy Collinson, Head of Electron Microscopy at the LRI; Anne Weston, Senior Scientific Officer; and Charlotte Collier, Photo Library Officer.

Share this article

Comments

Judith Ogus March 18, 2010

Hello. Your images are beautiful – helps me adjust my own images of cancer at a cellular level. I am trying to contact Anne Weston. I saw her photo of the lung cancer cell in Science Magazine and I have described it in an as yet unpublished post for my illustrated blog the cancer experience. I would like to get her permission to either draw a cartoon of the image for my blog – http://nucancerfrogblog.randomarts.biz – or to use her image and to reference links to her other images.Can you help me contact her? Please visit my blog – I have created it for people who are involved with cancer in any way. The protagonist is a frog – it is like no other blog you have seen. I promise! Feel free to contact me via my email address.

Thank you, Judith

Kat Arney July 22, 2009

Thanks Jo!

Kat

JoBrodie July 22, 2009

What a lovely post Kat – the cells are rather beautiful, almost like little 3d textiles. Shame they’re not as nice in ‘real life’ as they are in the pictures though! Also enjoyed the explanation of electron microscopy – I had some scans made for me once of some cells and was stunned to see the results, and fascinated by the process.

It required me to take some peculiar solutions away with me to the lab to fix my cells before bringing them back to the EM lab for processing and microscopy. I think osmium compounds were involved.

My samples were photographed using the technique where you can see the organelles inside – I had perfect, textbook mitochondria (http://en.wikipedia.org/wiki/Mitochondria) in my cells.

Anyway, beautifully explained and imaginatively illustrated :)

Jo

Kat Arney May 9, 2009

Simon,
I’m not sure about the purpose of the cell that was featured on the front of Nature or the ones in the video, as these were images from the EMU that had been contributed to our photo image library. However, the EMU provide microscopy services for many different researchers. Here are just a few examples of papers that have used the skills of the EMU. I’m afraid that we can’t show the images from the papers here, as the journals hold the copyright.

Leverrier et al (2007) Role of HPV E6 proteins in preventing the UVB-induced release of pro-apoptotic factors from the mitochondria. Here the EMU team made detailed TEM images of skin cells that had been infected with Human Papillomavirus (HPV), showing how the virus prevents the cell’s ‘power factories’ (mitochondria) from breaking up when the cells are exposed the UV light, compared with uninfected cells . This research is shedding light (pardon the pun) on how the virus hijacks skin cells, and leads to certain types of skin cancer.

O’Shaughnessy et al (2007) AKT-dependent HspB1 (Hsp27) activity in epidermal differentiation. In this paper, the EMU team used TEM to look at tiny granules of two specific proteins within skin cells, showing that the two proteins are found together. They used a technique called immune-electron microscopy, in which antibodies (which can recognise specific molecules) labelled with metal particles are added to the cell samples, to pick out specific proteins.

Williams et al (2007) Membranous structures transfer cell surface proteins across NK cell immune synapses. Here, scientists were studying how immune cells communicate with each other – this is very important, as the development and treatment of cancer is closely linked to the immune system (as we’ve blogged about http://scienceblog.cancerresearchuk.org/2008/10/08/ncri-lecture-good-cop-bad-cop-the-immune-system-and-breast-cancer-spread/ ) In the paper, the EMU team used SEM to get a detailed view of the contact between immune cells, revealing how proteins may be transferred between cells.

Cross et al (2008) Viral pro-survival proteins block separate stages in Bax activation but changes in mitochondrial ultrastructure still occur. In this paper, the researchers were studying apoptosis – the process of controlled cell death. This process is faulty in cancer cells, which do not die when they should. The EMU team used TEM to look at the mitochondria within cells as they undergo the death process (the mitochondria break up and release toxic proteins into the cell which lead to apoptosis). Thanks to the images obtained by the EMU, the researchers were able to tease out the timing of crucial events in apoptosis.

These are just a few examples of how the work of the EMU is helping our scientists to understand more about the inner workings of cancer cells. Hope you found it interesting,
Kat

Simon K May 7, 2009

They’re fascinating and disturbingly beautiful images, and it’s amazing to read about how much work goes into preserving the cells and preparing them for imaging.

You talk a bit at the beginning about how these images are used by researchers – are you able to give a bit more detail about that? For example, the breast cancer cell featured in Nature – how does that differ from a healthy breast tissue cell, and what have researchers learnt from seeing the image?