osmotically-induced lysis. Students can investigate the effects of a range of different

concentrations of sucrose solutions on the appearence of the protoplasts.

1. Cut the lettuce into pieces and put them into sorbitol solution.
 
 
 

                     2. Incubate the tube at 37^oC water bath for 5 minutes.
 
 

3. Add 0.5 cm ³ of enzyme * then incubate for another 20 minutes.
 
 
 

                     4. Filter the tissue suspension through a funnel plugged with gauze.
 
 
 

                    5. Spin down the protoplasts to the bottom of the tube. Carefully pour away the
                        liquid from the top.
 

6. Resuspend the protoplasts in 0.1 cm ³ of sucrose solution.
 
 
 
 

  7. Look at the result.