Wednesday, February 6, 2008

fertilization

today i had an almost perfect fertilization with my super fertile fresh testes! in a petri dish of hundreds of xenopus eggs, only 2 did not fertilize. i'm so good at fertilizing eggs...muahahahah!

here's part of my job (i do this 3 times a week):
  • ~one week before fertilization, i inject a low dose of human chorionic gonadotropin into a female xenopus. this is to prime her, or get her eggs ready and at the same stage. (at first, i was really nervous about giving frogs injections, because you can't be like, "okay don't move, or it'll hurt more." but it's okay, seems like they usually can't feel the injection at all!)
  • the night before fertilization, i inject a high dose of human chorionic gonadotropin into the primed female.
  • the morning of fertilzation, i squeeze and massage the female, while aiming her butt at a petri dish. eggs come squirting out into the dish! (easier said than done. you have to grab both legs of the frog, split them apart and stretch them out so she can't kick herself out of your hands. and it's best if you cover her eyes so she feels safe. and you have to massage and squeeze her while you are at it. and you only have 2 hands. i am now an EXPERT at this!)
  • meanwhile, i drugged a male frog, cut it open, dissected out its testes, and stored the testes in the cold room. they can be used for up to 1 month!
  • i cut a small piece of a testis, mash it up with teethed forceps, and touch all the eggs with my testis.
  • i wait 3 minutes, allowing all the sperm to attach to the eggs.
  • then, i flood the dish with water. the osmotic shock makes the eggs take in the sperm!
  • ~1.5 hours later, the single cell eggs should have begun to divide into two cells!
  • and my embryos are on their way to growing up!
these xenopus embryos are in two cell stage. i stole this picture, but this is pretty much what my embryos look liked. unfortunately, many times, instead of looking like this, the the embryos are all rotten and smelly.

1 comment:

shauna said...

wow! i feel like i'm in osmotic shock myself. i understand now what you mean by "frog rapist" :p don't let the animal rights organizations see this.. ahhahaha