Preparation of slide for study of internal structure of stem, root and leaves of dicot and monocot plant.

 Aim of Experiment: Preparation of slide for study of internal structure of stem, root and leaves of dicot and monocot plant.

Principle: The study of internal morphology, i.e., cells of various tissues in an organ of a living body is called Anatomy. Tissue, which is a group of cells performing a common function, may be simple (parenchyma, collenchyma and sclerenchyma) or complex containing more than one type of cells (xylem and phloem). The tissues may be temporary (meristematic) or permanent (sclerenchyma, parenchyma and collenchyma).

The internal organisation of these tissues differs in root, stem and leaves. These differences are given in tabular form for easy identification. Various tissues which constitute roots and stems are described briefly.

Material Required : Preserved material of sunflower root and stem, maize root and stem, microscope, sharp blade, slides, watch glass, coverslips, safranin (1gm in 100ml of 50% ethanol), brush, glycerine, blotting paper

Procedure :

Sections Preparation

·        Collect a few thin young part of plants (i.e., non-woody/herbaceous without any secondary growth).

·        Use potato piece/Calotropis stem pith for embedding the material to be sectioned. If material is thick, it can be directly sectioned without embedding them in pith.

·        Hold the material between the thumb and index finger in such a way that the tips of the finger and smooth cut surface of the material are in a line, while the tip of the thumb is just a few mm below the upper surface of the material.

·        Wet the surfaces of razor blade/scalpel blade.

·        Carefully move the blade horizontally over the surface of material in quick succession in a manner that a very thin and complete slice of the material is cut and obtained over the surface of razor blade.

·        After cutting several sections in this manner, transfer all these into a watch glass containing water.

Staining of Plant Material: Make a visual observation of the sections cut and pick the thinnest possible and complete sections and transfer it into a watch glass containing safranin and allow these to remain there for about 2 minutes.
With the help of a brush gently transfer the section into another watch glass containing water to remove excess of safranin stain.

Mounting: On a clean slide, place a stained section in the middle of the slide in mounting medium
containing one drop of glycerine usually. Using a needle, slowly places the coverslip.
An excess of water or glycerine from the edge of the coverslip can be removed by placing
blotting paper.

Precautions:

·        While working with sections, use a brush.

·        Gently place the coverslip in order to avoid air bubbles.

·        Excess glycerine can be removed with filter paper.

·        Root parts should be stained before sectioning.