Leaf scrape Flashcards
What is a leaf scrape used for?
To isolate an epidermal layer for viewing under a microscope.
Describe the procedure of the leaf scrape.
1) Lie a blade of grass flat on the microscope slide and irrigate with water using a dropper pipette.
2) Using the safely blade vertically, gently sweep the blade along the top of the grass removing tissue from along its length.
3) Repeat this with the blade always coming the same direction adding water to reduce friction.
4) When enough layers of the leaf have been removed, the green colouring will have disappeared as only the EPIDERMAL layers are left.
5) Examine the epidermal layer under a microscope. You should see the epidermal layer, stomata and possibly leaf hairs.
Why do some parts appear colourless and other appear green?
In the parts that look green not all the mesophyll has been removed (as this contains chlorophyll)
Why do you irrigate with water?
To reduce friction between the blade and the leaf.
