I remember when I was maybe 7 or 8, I got my first microscope.. My parents had gotten me a kids microscope kit and I spent hours upon hours with that little microscope over the next few years. We had a pond on the farm and I still remember putting a sample of water from that pond on a slide. It was like looking into a different world. Who knew that water had so much life that is invisible to our eyes. In reality my life has not changed too much. I still look into a microscope weekly at work and seeing something that you cannot see without that piece of equipment is still something that never gets old. Maybe that is why I love my telescopes so much as well. There is is just something about seeing the "unseeable" and exploring the unexplored that is just part of human nature.
I just attended a scientific conference called Society of In Vitro Biology. This conference is held once a year and is always a great place to hear about some of the newest advances coming out of the in vitro (taking place in a test tube or petri plate) biology community. As I was listening to the Keynote Speaker, I realized that there are explorers we all know and understand like Neil Armstrong or Christopher Columbus. However there are also scientific explorers that are not everyday names (at least in the general public) that are exploring the unknown just as much as the Armstong's. I had the privilege to hear one such explorer who is literally seeing the "unseeable" and brought me back to my childhood memories.
William E Moerner won the Nobel Prize in Chemistry in 2014. So for Dr Moerner, the literal million dollar question was how can we see the "unseeable" even better than we already do. And from this point on, I have to admit my brain can only comprehend Dr. Moerner's work at a very basic level. I understand his full body of work about as much as my 1 year old daughter understands my cell phone. She doesn't really know everything it can do, but knows just enough to push buttons and pretend to talk on it. So I will try to take the very basic concepts I heard and keep to the basics.
When I was that kid looking in my microscope, it had limits. I could see those little Paramecium in the pond water, but I couldn't see everything with my basic microscope like bacterial cells. My microscope couldn't resolve something that small. In school we had microscopes that could actually see a bacterial cell after we stained it, which was call Gram staining. Now we can even "stain" by "tagging"cells with a protein that fluoresces or glows under certain light. Remember your black light in college? This is basically the same concept. Certain proteins glow under certain lights. A common florescence protein comes from a jellyfish and is called GFP or green florescent protein. The jellyfish has a protein that really does make it glow under certain wavelengths and we can get that protein to express in other organisms. This type of tagging is used very commonly in science as a tool to see things under a microscope with the benefit that your organism is "stained" and can still be alive. Things like Gram-staining kill the cells.
Here is an example of bacteria have been tagged with GFP and are photographed under a microscope in the presence of a certain type of light. It is really cool to see this!
 |
http://2013.igem.org/wiki/index.php?title=Team:Newcastle/Parts/HBsu-fp&oldid=349853
The problem wth optical microscopes is they have a limit and that limit is based on wavelength of light. So anything under 250 nanometers in length is going to appear blurred under a microscope. This is the diffraction limit and is just physics in action. This is where our explorers step in. They find ways to break limits.
They used those florescent tags and found ways to turn the florescence on and off. Think of an late summer night and watching the fireflys blink on and off in your yard. If a bacteria cell is tagged all of the place with these these florescent proteins and you can make the flourecence turn on and off you will have blinking. The movie shows exactly what is happening.
|
Now you can take a picture of each of those of molecules as they blink. You will have many pictures and can reconstruct and merge all the pictures.The results will be your object such as a bacterial cell that is up to 10 times more resolved than just a typical optical microscope image. Below is a picture that shows a much more resolved bacterial cell using this technique.
 |
| http://web.stanford.edu/group/moerner/sms_smacm.html |
There is a lot of science of science that went into this including how you make the florescent proteins turn on and off and how you reconstruct the images. I kept this very basic mostly because I can really only comprehend the very basics of what Dr. Moerner and the other 2 scientists that won the Nobel prize in 2014 did. There are all sorts of ramifications this research has and will have on scientific experimentation. In the end, it was an amazing feat that shows what science is really about. It is about explorers whose mission can be taken straight from science fiction: "to boldly go where no one has gone before." And of course splitting the million dollar Nobel prize for your contributions to science and humanity is also a nice perk of being a scientific explorer.
