CELLULOSE-PROTEIN COMPLEXES 253 



DISCUSSION 

 M. V. Edds, Jr., R. D. Preston 



Dr. Edds (Brown University): How do you separate the lamellae of the 

 Valonia cell wall in preparation for electron microscopy? 



Dr. Preston: The separation of lamellae of the Wdonia cell wall is com- 

 paratively easy. A square is cut out of the wall and is left to dry down on a 

 glass slide. A piece of Cellotape is then pressed on the wall and, on peeling 

 the Cellotape from the slide, some of the wall remains on the Cellotape and 

 some on the glass. The process can be repeated until a thin lamella is left 

 either on the Cellotape or on the glass. This lamella can then be separated 

 from the glass by flotation in water, or from the Cellotape with appropriate 

 solvents. A more reliable method, however, is to mount a piece of wall so 

 that the part of it to be examined overlaps a hole in a piece of adhesive paper. 

 Stripping by Cellotape then leaves the final lamella projecting over the hole 

 without ever coming into contact with either glass or Cellotape. 



Alternatively (and better), the lamella can be teased off in water, using 

 fine steel needles. This requires considerable manipulative skill, but produces 

 a preparation with a minimum of distortion and without any contamination by 

 Cellotape. 



