Class is in Session

I thought it might be interesting to show you a little bit of what I do since most people's eyes glaze over when I mention I'm studying molecular biology and viruses. Most of the time, the things we do quite appropriately lead to glazed eyes, as they are not very visually interesting, unless you consider small lines in a block of Jello interesting.

However, in my Virology lab we have been doing some stuff this last week that is cool both scientifically and aesthetically, so I thought I'd take the opportunity to share with everyone. We have been learning to use techniques involved with Immunofluorescent Microscopy. A big word for using antibodies to make what we are interested in glow. In one of our experiments we used 3 different dyes to make 3 different parts of the infected cell glow.

In an aside, some basic cell biology. There are two main areas of a cell like the ones we are looking at, the cytoplasm where all the metabolism of the cell occurs and the nucleus, where all the DNA is housed. Think of it sort of as the shop floor and the managers office.

With our first dye we stained the cytoplasm (or shop floor) using a red dye. This allows us to see where the cell is located and the general outline of the cell.

With the next dye we stain the DNA of the cell blue. This allows us to locate the nucleus (managers office) of the cell. Finally we used a green dye to stain the virus we were using a bright green. This allows us to see where the virus is located. In this picture it is Adenovirus 2, a relative of the virus that has been making news down in Texas, but generally only causes a cold.

Now while each of these pictures is a lovely color, alone they do not provide us with much information other than the fact that our sample contains cells, DNA, and virus. In order to be able to extract more information we use a nifty trick in which we overlay pictures of the same group of cells at the same magnification, but using the 3 different dyes to visualize all three items of interest. We have to take each color seperately and then use a computer to overlay the images to produce a composite of the 3 images. This allows us to see not only the structures but their spatial relationship with each other. In the case of this final picture the blue and the green combine to form a white color. If you look closely you can see a dark red color in the background that is the cytoplasm and the virus and DNA combine to form the brighter circles. Because we see that the DNA and virus are located in the same place, we can hypothesize that the virus must be located in the nucleus, and sure enough research has shown that Adenovirus replicates in the nuclei of infected cells.

In a second experiment we stained Herpes Simplex Virus, the one that gives you cold sores growing inside some cells, here you can clearly differentiate between cells that are infected with virus (stained green as above) or cells that are not infected with virus. Can you tell if this virus replicates in the cytoplasm or the nucleus? If so, then I have effectively taught you something and we're both better off for the experience.