Alternative Stomata Preparation: Reprinted from:  Brewer, C. A. 1992. Responses by stomata on leaves to microenvironmental conditions. Pages 67-75, in Tested studies for laboratory teaching. Volume 13. (C. A. Goldman, Editor). Proceedings of the 13th Workshop/Conference of the Association for Biology Laboratory Education (ABLE), 191 pages.

 

  1. Select a plant that has been kept in the light and label the container of the plant "LIGHT." Clip two leaves from this plant. Prepare casts of the leaves surfaces by painting the top surface (adaxial) of one leaf and the bottom surface (abaxial) of the other leaf with clear fingernail polish. It is important that nail polish only be applied to dry leaves or the replica will be cloudy and may not dry properly.

    Allow the finger nail polish to dry for about 10 minutes. Note: Casts will be very difficult to remove if you allow the nail polish to remain on the leaf surface for more than 15 minutes.

     

  2. While the nail polish is drying, label microscope slides as either adaxial (top of the leaf) or abaxial (bottom of the leaf).

 

  1. Cut a piece of Scotch tape approximately 1.5 cm in length. Fold the tape over on itself leaving 0.5 cm of sticky surface exposed. Place the sticky tab of the tape at the edge of the leaf so that it sticks to the nail polish cast (Figure 3.3). Use the remaining tape as a handle to carefully pull the nail polish cast from the leaf surface. You will use the portion of the cast not covered by tape to view stomata.


[View Larger Version of this Image (18K GIF file)]

Figure 3.3. Procedure for lifting a surface cast from a leaf surface.

  1. Place the cast on the appropriately labelled slide. Place a coverslip over the cast. (If you would like the slide to be permanent, place a small drop of nail polish on each corner of a coverslip. Then cover the cast with the coverslip so that the nail polish glues the coverslip to the slide.) Repeat this step for the remaining leaf.
  2. Examine the slides under high power to determine which leaf surface has stomata. Carefully survey the entire leaf cast. The leaf surface with stomata should look similar to one of the illustrations in Figure 3.4. For future observations, it will only be necessary to make nail polish casts from the leaf surface with stomata.