Biology 101: Don't Drink your experiment

[Jonathan Kui]

The project I am working on now involves tagging specific cells within a fly's brain and making them glow green using GFP. I take 50 flies and manually dissect out the brains from the heads. I get the brains floating about and break off the brains into single cells using all sorts of horrible chemical digestion until I've got this soup of floating cells which I then bring to an onsite flow-cytometry facility which sorts the cells based on their colors. If they glow we keep them.

So my goal was to try and see if we could isolate specific cells from the brain using this method. Now this is a fairly lengthy procedure and to get this done you need to set up an appointment at the facility well ahead of time- so I was looking at a 10 o'clock appointment. Now dissecting 50 fly brains is no trivial matter. I have been doing it for a few months now and it still takes me about on the order of 3 hours or so to dissect out that many fly brains. Also, I wanted to give myself a margin of error so I got up at about 5am. I got to the lab by 6 and had surgical tools in hand by 6:15.

So I take these fifty flies that don't know they are about to meet their demise. They had been going about their merry business for a couple of days already. So here I come in at the crack of dawn, gas them all till they become unconscious, yank off their heads which is pretty gruesome, if you are doing it early in the morning, and throw them into this liquid so that they are starring at me and I sharpen my surgical tools feeling pretty awful about myself. It is a moment of self examination and I think, am I really going to do this again. Well, one by one I crack the heads open; yank out the brains and at about 9a.m. I am almost done. The heads are floating in the solution already; the labor is done, so now comes the simple part. I wash the brains and then I add the chemicals which break them apart. Then I pipette up and down very rapidly to get the physical force to break the brains apart. For the most part they are just this opaque mush so we have to take all this liquid and put it in a cold tube and let the chunks of tissue, the brain chunks, settle to the bottom of the tube.

So I look at the clock and now it is 9:45 and the tube is on ice, the brain chunks just have to settle down. All I have to do is pipette out the individual cells in the solution, this would be the simplest thing in the world. Oh I should mention that the tube is fairly opaque, the liquid itself is a milky color and the brain chunks are each the size of a poppy seed. The brain chunks are white so I am looking at white chunks of brain floating in a milky solution in an opaque tube and to see these chunks I am holding the tube up to the light, a white florescent light, so this is not working too well. I've got my collection tube where I will put the single cells in my left pinky so using my left forefinger and thumb I am holding the larger tube up to the light and I'm squinting (and I'm Asian so that's pretty natural for me and if an Asian has to squint you know its bad).

I am getting most of the liquid out with my pipette but there still is a bit left and I am looking at it and saying, "If I tilt it a bit I will be able to see it more clearly." I put what liquid I can into my collection tube which I am still holding with my pinky and I am holding the tube up to the light for that last couple of drops and as I am holding it there and tilting a bit the next thing I know I taste something cold and salty that dripped into my mouth and my first thought was, oh no, and then I realized that I had just poured my collection tube, my three hours of dissection, my fifty brains, my four hours of work at the crack of dawn, into my mouth and then I thought, oh god no!! And I spit, trying to get this out, these bunches of cells, the blood serum, the salt, and a few dissociating chemicals.

Half of my sample was lost because I literally poured it into my mouth. Fortunately I took what was left in my tube, so it was not a complete loss. You know you have the old adage, my dog ate my homework, but you don't have the I ate my fly-brains. It was funny but at the time I was thinking how am I going to tell my boss and what would health and safety think about this story? I mean what a coincidence I can't even toss popcorn into my mouth with precision!