Matthew Garrett (mjg59) wrote,
Matthew Garrett

People rarely ask me about my amazing ability to remove fruitfly ovaries in under 10 seconds. "This skill makes me strangely attracted to you" they then inevitably fail to add, thus giving the lie to claims that a PhD in biology is a great way to impress women. In order to avoid future social embarrassment I have therefore decided to provide a step-by-step guide to removing ovaries from any fruitflies you may have to hand.
  • Feed your fruitflies. Fruitflies like yeast, so give them a pile to munch on. A well-fed fruitfly is a happy fruitfly.
  • A happy fruitfly is a fertile fruitfly, and has bigger ovaries. Since fruitflies are small, this makes your job easier.
  • Knock your fruitflies out with carbon dioxide. When doing this, ensure that you don't knock yourself out with carbon dioxide.
  • Separate your fruitflies into male and female flies. Female flies have larger abdomens and striped posteriors - male ones are thinner and have solid black markings.
  • Dispose of the males. They don't have ovaries. Local laws may make it awkward for you to release animals from laboratory environments, so dump them into a bottle of ethanol. They'll probably die happy, to the extent that fruitflies can really be happy.
  • Etherise the female flies. When identifying ether, try not to do so by smelling it.
  • Once the female flies are thoroughly dead, transfer one to a small watchglass containing a quantity of phosphate buffered saline with a small quantity of detergent in it. Place this under a low magnification microscope.
  • Grip the neck of the fly with a set of needle-nosed tweezers. Grip the very rear of the fly with another set of needle-nosed tweezers.
  • Slowly move the tweezers apart. If you are lucky, the abdomen will split and you'll start pulling out internal organs. If you're unlucky, the head will come off. In this case you should move the first set of tweezers further down the body and try again.
  • Continue pulling out internal organs until you find two objects that look like bunches of bananas. These are the ovaries, with each "banana" being an egg chamber containing an egg and associated support cells.
  • (If your fruitfly contains no ovaries, it's not a female. Try again)
  • Carefully separate the ovaries from the other chunks of tissue that are stuck to them, and transfer the ovaries to a tube containing phosphate buffered saline.
  • Repeat until you run out of flies. Note that towards the end, it will become tempting to just tear the flies into small pieces rather than removing their ovaries. Bear in mind that the aim is to obtain fruitfly ovaries, not to kill flies. There are much easier ways of doing the latter.
  • Dispose of the remaining bits of flies in accordance with any relevant legislation. Do not throw remaining bits of flies at coworkers.
  • Fix the ovaries in formaldehyde and suspend in methanol. Freeze at -20°C.
See? It's all very easy.

(Note: This protocol involves chemicals known by the state of California to cause cancer, birth defects and general fucked-upness. Do not ingest methanol unless you want to demonstrate competitive inhibition in the form of a bottle of vodka. Value of fruitfly ovaries may go up as well as down. Do not taunt fruitfly ovaries)
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