Procedure
- Find out which group you are in, and which of the eight operations shown below you are to perform.
- Have one member of the group record the number of the group, number the operation, and date on the top of the petri dish with the grease pencil provided.
- Obtain a slide, four lens papers, scalpel, dropper and camel's hair brush.
- Prepare an "operating table" by wrapping a lens paper around the microscope slide as demonstrated by your instructor.
- Using the camel's hairbrush, carefully transfer a planaria from the petri dish to the operating slide. Then place the slide on the stage of the dissecting microscope.
- Allow the planaria to become extended on the slide, but do not let it dry out. When it is fully extended, make the desired cuts quickly and cleanly. In the case of operations that do not completely separate body parts, be sure to hold the blade in the cut for at least five seconds to prevent the pieces from healing in their original position.
- When the operation is complete, rinse the pieces of planaria in the petri dish with a gentle stream of water from the dropper. Never use a hard instrument to scrape them off.
- Replace the lid on the petri dish and place in a shaded area at room temperature.
- In operations 4 through 8, where the body parts are not completely separated, it will be necessary to renew the cuts during the first three days to prevent the parts from healing in their original positions.
- The entire regeneration process will take approximately one month. During this time the planaria ARE NOT TO BE FED, and should be disturbed as little as possible.
- Because the planaria foul their water rapidly, it will be necessary to change the water twice a week. Gently pour the old water from the dish, and rinsed the aged tap water. Be careful not to wash away the planaria that will cling on the bottom of the dish. Refill the dish with afed tap water.
- During the regeneration process, observe the planaria as often as possible.