Planaria Cutting Protocol

1. Fill several petri dishes with water and place in freezer.
2. Remove a frozen plate and make sure the surface of the ice is relatively level. 
3. Pour room temperature spring water (or whatever water you use with the planaria) over the plate a few times to increase the ice surface temperature a bit.
4. Cover the plate with plastic wrap and tap it down till it adheres and conforms to interior shape of the plate (but make sure the edges of the wrap are underneath the plate so excess water won’t flood the inside surface).
5. Fill an extra deep empty petri dish with spring water and set aside.
6. Using forceps, dip a filter paper disc into the second dish to saturate it with water.
7. Place the disc on the plastic-covered ice plate, and remove excess water using a plastic pipet.
8. Cut the tip off a second plastic pipet and use it to pipet several planaria onto the filter paper disc.
9. Working quickly under a dissecting scope, use a scalpel and dissecting blade to cut each worm just before the pharynx (after the auricles or “ears”) and just after the pharynx (before the tail).
10. After every 2^nd or 3^rd worm, wipe the blade on an ethanol-soaked paper towel to remove slime.
11. When finished, pick up the disc with forceps and shake off the worms by immersing the disc in the second petri dish filled with spring water.  You may reuse the disc as long as it is not too damaged.
12. When you have a sufficient number of worm fragments (I think a 100x20mm petri dish holds about 75 worms, so you can cut up about 25 worms for each dish), carefully pour out the water but keep the worm fragments in the dish.  Refill the dish.
13. Examine worm fragments under the scope and remove any dead or heavily damaged pieces.  Make sure the rest are sufficiently cut.  If not, remove and cut again on ice plate.
14. Label petri dish with date, time of cut, and original number of worms.
15. Place dish in incubater.