Make a Clear Leaf – How to View Vein Structure

Handouts and Guide

Below are the handouts for your students and a teachers guide for the preparation leading up to the lab.

Leaf skeletons - What You'll Need

Ever wondered how to make a leaf skeleton, or a cleared leaf? It's easy to do and makes a great micro-lab for your students. It's also light on the supplies required. In fact, many of them are free or quite inexpensive, making this a great lab for any school on a tight budget.

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    Beaker
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    Hot plate
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    Small brush
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    Leaves - thick, waxy leaves are the easiest to work with
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    Bleach - not required
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    Sodium Hydroxide or Sodium Carbonate (washing soda)
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    PPE - Gloves, Safety Glasses, Lab Coat - These are the minimum required items. You must always optimize safety for your lab environment.

A nice image for Pinterest:

Procedure

You'll want to start this procedure the day before you have your students do the lab. The leaves need to simmer for about 2 hours, maybe more depending on your leaves.

Here is the procedure we used to create the leaves on this page. Expect the maple leaf. For the details on how it was done read below.

  • Dissolve about 10g of your base in 300 mL of water. This should be enough liquid for 10 to 15 leaves, depending on their size. You can scale this up if you're treating a large number of leaves or if your leaves are large.
  • Bring the water to a simmer; approximately 240C with slow stirring for us. We like to cover the beaker to reduce evaporation.
  • Let the leaves simmer for about 2 hours. The exact time will vary widely depending on how strong your base is and what leaves you use. You'll need to experiment a bit to find the right time for your conditions.
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    You'll know the leaves are ready when you start to see brown chunks of leaf lamina floating in the solution. 
  • Carefully remove the leaves with a spatula, stir rod or some other smooth surfaced tool.
  • Place the leaves in a shallow pan or another beaker for rinsing.
  • After rinsing, the are ready to be brushed, more correctly, dabbed. 

Use the brush in a dabbing motion rather than a brushing motion. Dabbing will remove the loosened material, brushing will tear the leaf.

  • It's helpful to have the leaf in a shallow dish of water during the dabbing.
  • After you've removed as much of the lamina as you'd like to, the leaf can be placed in bleach for several minutes to turn it white, or orange as our leaves did. This step is not needed and may be best left out if you'd rather avoid the odor of bleach floating through your classroom.
  • After bleaching you'll need to perform another rinse cycle.
  • Place the leaf on the surface of your choice for drying and viewing.

Leaf Structure

Below are two useful images showing a variety of leaf morphologies and leaf micro-structure. Click the image for a larger view to show your class.

Leaf Morphology

Maple Leaf

The fine structure of the maple leaf was preserved by using a gentler, but much longer, method. Sodium bicarbonate was used rather than sodium hydroxide. The leaf was simmered for approximately 10 hours over the course of a few days. It was then rinsed, bleached and rinsed again. Finally it was allowed to soak in water for about a week. After soaking the lamina was soft enough to be removed with the brush.

Need Some Leaves?

Buried in ice and snow? Don't have leaves nearby? No problem!

Send us an email and we'll send you some leaves. Just let us know how many students you have and where to send the leaves.

Image Attributions

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