OBJECTIVE: The student shall demonstrate their ability to perform delicate lab work by isolating the mitotic apparatus of the developing sea urchin embryo.
PURPOSE: Sea urchins have been used to study mitosis for over a hundred years. This lab provides experience performing a delicate manipulation of the embryo as well as providing a new technique for further study of development.
SET: So far the work we have done has been fairly easy. Today we separate the technicians from the researchers [techs usually perform better here]. Even some college students have trouble with this technique, but if we can get it to work, it will allow us to peer deep into the developing embryo to see in greater detail, the process of cell division.
MODEL: Demonstrate the entire technique.
STRUCTURED PRACTICE: Have students ask questions as you go along.
GUIDED PRACTICE: Have students perform isolations themselves.
CLOSURE: Before the advent of the electron microscope and molecular biology, this was the best way to see the processes of cell division in the sea urchin. Up until just before his death in June 1996, Dr. Daniel Mazia was using this very technique in continuing work with the sea urchin.
INDEPENDENT PRACTICE: Have students propose and perform further experiments using this technique.