Elizabeth’s BioBlog

    The Drosophila embryo is an oval structure of about 500 μM in length and has a diameter of about 180 μM. Think of it this way, a grain of rice is about 5000 μM long, which means you can roughly fit 10 embryos on top of it. The first image shows a fruit fly laying an egg. It gives you an idea how big the egg is compared to the fly. Now that you get the picture, imagine trying to dissect it. Sounds hard, right? It is.

I spent a big part of last semester trying to learn the technique of dissecting the embryos and I haven’t fully achieved it yet. But I’m getting there! How exactly is this done? The dissection tools, or “Embryo Torture Devices” as we call them in the lab, are basically two heat pulled capillary tubes that make for very fine tipped “scalpels”. The embryos are placed on a microscope slide in a little “pool” made with tape, slightly covered with water, and placed under the dissection microscope. With the pulled needles, one has to try to hold the embryo still with one of them, and use the other to make a vertical cut with just the right pressure. An excess of pressure will cause the embryo to burst. Then (and this is the part I’m still working on), with the pulled needle, one has to take the “flaps” on either side of the vertical cut and pull them open to expose the interior of the embryo. Again, I remind you that this is under the microscope with a 500 μM long object.

    The purpose of this technique is to be able to do an in vivo analysis of the processes going on at the time of neuromuscular synaptogenesis. I will be using this technique further down the road for certain parts of my project, so I better practice.