OBSERVATION THROUGH THE MICROSCOPE (optional)
MATERIALS
- some clean microscope slides;
- hook made with a long metal wire;
- dye to stain the nucleus (ex: Toluidine, Methylene Blue, Aceto-Orcein);
- dropper;
- microscope.
METHOD
- with a long metal wire ending with a hook, extract a sample of DNA from the tube and place it on a clean microscope slide;
- level the mass on the slide and stain it with a nuclear dye;
- if necessary, add a little water and mount the coverslip.
By observing this preparation under the microscope, do not expect to see the well-known double helix ladder structure of the DNA. You cannot see it even with an electronic microscope. What you will see are clumps or flocks of DNA material which look like a tangled mass of protein strands as illustrated Figure 12.