How to Dissect a Frog

by jackthursby in Workshop > Science

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How to Dissect a Frog

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A video at http://youtu.be/yVguMzp25mU

This Is less project and more a good working practice or operating procedure for the necrosis of a frog.  The frog depicted in this instructable (Xenopus laevis) is a pretty good muse as it has all the normal bells and or whistles, but in a larger format.  Which makes it a LOT less fiddly than when preforming the procedure on smaller animals --  such as Xenopus tropicalis.

These animals where marked to be culled for several reasons. High on that list was poor egg production and age.  The youngest one being ten years old. A very old frog, a much longer life span than any found in the wild. All these animals where used exclusively for breeding, we weren't trying different shades of blush to see which brought out their cheek bones. I personally cared for every aspect of their lives, as any good Animal Husband would. They were loved and culled in the most human and stressless way I possibly could.

And rather than cull then throw them in the rubbish, I used them to create this teaching tool. As well and allowing some of my work-study students the opportunity of first hand dissection. Which is rare in today's universities.


Tools

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The most basic kit is the best kit:

Scissors S/S (s/s stands for sharp / sharp. meaning it has two shape blades)
Tweezers

The other stuff

Gloves
Paper towels
Dissection board (If you feel like it. When performing an necropsy, I just use a paper towel)

In the video, you will see the use of a razor blade. This is only because we couldn't find where I had hidden the snips. I did find them later.  

In the Beginning

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Use the tweezers to pinch a bit of skin near the thigh, nick the skin with the scissors.  Insert the tip of your snips between the skin and the abdominal wall. Cutting to the left to avoid the mid line, cut the skin up to the jaw. 

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Repeat cuts 1-3 on the abdominal wall. But as you cut the base of the mid vein, flop it to one side, so it does not drain into the abdominal cavity. Stretch out the flap and make the 4th cut so it lies flat and to the side neatly.

Hopefully, it looks a little more like Dr Frankenstein than Jack the Ripper.    

The Kill Stroke

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At this point it's prudent to finish the beast. Locate the heart under the breast plate and cut it free from the frog.

A frogs heart is a magical thing.  Vibrent silver in appearance, it has such a remarkable pacemaker, it will keep beating 10-20 mins after cutting it free.  And even after stopping it, you can try poking it, and it most likely, will start again. 

Video

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