So maybe I’ve been spending a little too much time alone in the microscope room, and it’s been way too long since I’ve been to an art museum, but snail teeth are really pretty when you’re imaging them at super high magnification and resolution. Maybe it’s also all the time I put in to get my samples to the stage where I could image them in the Scanning Electron Microscope (SEM). The more time and effort something takes, the more rewarding the result, right?
So, a couple posts ago I told you about the preparation process for SEM and sectioning, and for the last week I’ve been taking the next steps; imaging my
samples in the SEM and embedding and sectioning actual pieces of tissue and whole limpets instead of just paraffin blocks. Both are pretty basic procedures that just take concentration and repetition , so I just turn some music or a podcast and plug away at tweaking the SEM settings to get the best photos of my samples until I notice my concentration is fading. Then it’s time to switch to sectioning. After I sliced through all the different chunks of tissue and got the hang of slicing through a block that has something other than just paraffin in it, it was time to prepare for serial sectioning. This is when you take a whole
animal (a small one), a limpet in my case, embed it in paraffin, and then slice it so that you end up with a series of sections that take you from one end of the animal to the other. By slicing in different directions you can get different perspectives on the anatomy and learn something different than what you could just from dissection alone. What do I do when I’m burnt out on sectioning too? Well, I just left the sectioning room, so I guess then I switch to blogging about it…
A third way to look at soft anatomy is SEM, and that’s the next thing I’m going to learn from Sasaki-sensei. With dissection, you get a sense for the overall layout of the tissues and organs, with sectioning, you can get a more fine-scale picture once you’ve stained the tissues and made
the cells visible under a light microscope (the typical kind of microscope we’re all familiar with from science class), and then SEM provides a picture of the surface detail of the tissue we’re interested in and the three-dimensional aspects we can’t grasp from sectioning and are on too fine a scale to see under the dissection microscope or the light microscope.
Why am I spending so much time just to be able to see parts of these critters?
I’ve been asking myself this question a lot lately. I have to keep reminding myself that what I’m really interested in is the evolutionary history of this group of limpets. Why are they so diverse? How were they able to become so successful at exploiting so many different kinds deep-sea habitats? But to get at these bigger questions, they need to first be broken down into smaller ones. Questions whose answers can then be pieced together like a puzzle to give me that big picture of the path this group of creatures followed to get to where it is today. I’m working on making those first puzzle pieces… it’s going to be a long road indeed.
Another reason is just to make pretty images of things we can’t observe with our own two eyes. If you want to see some really awesome and colorful SEM and other nerdy art check out these two websites, Molecular Expressions and Gajitz. You’d be surprised at how beautiful and complex beer and other random things look at super high magnification.