required practical 2 - mitosis

• what is the method of this practical?

  1. heat 1 mol dm-3 HCL at 60 degrees in a water bath
  2. cut a small sample of root tip using a scalpel
  3. transfer root tip to HCL & incubate for 5 minutes
  4. remove from HCL & wash sample in cold distilled water & remove the very tip using a scalpel
  5. place the tip on a microscope slide & add a few drops of toluidine blue stain
  6. lower the cover slip down carefully into slip
  7. place under a microscope & set the objective lens on the lowest magnification
  8. use the coarse adjustment knob to move the lens down then fine adjusment to re-focus until clear
• why should the cover slip be lowered carefully down onto the slip?

  to make sure no air bubbles which may distort the image and the coverslip does not slip sideways which could damage the chromosomes
• why is the blue stain added?

  to make chromosomes visible and will show cells undergoing mitosis