Module 02: Quadrant 02: Content Summary

Summary of

Module 2: Microscopy and staining Techniques

Part 1: Micro Slide Preparation (Whole Mounts, Smears, Squashes)

Objective: To learn slide preparation techniques for microscopic observation of plant specimens.

1. Whole Mounts: Used for minute plant specimens like algae, small leaves, and flower parts.

   • Temporary Mounts: Short-term observation with water as the medium.

   • Semi-permanent Mounts: Last for a few days, use glycerin, and seal with Canada balsam.

   • Permanent Mounts: Two methods—Hygrobutol and Glycerine-Xylol, involve fixation, staining, dehydration, and mounting for long-term preservation.

2. Smears: Used for preparing single-cell specimens (e.g., bacteria, blood cells). The sample is smeared across the slide and fixed, allowing for cell observation and analysis (e.g., chromosomes).

3. Squashes: Ideal for studying internal plant structures like mitosis/meiosis (e.g., onion root tips). Samples are squashed under a cover slip to observe cell division stages.

Part 2: Plant Microtechnique (T.S., L.S., R.L.S., T.L.S.)

Objective: To study transverse and longitudinal sections of plant tissues for anatomical observation.

1. Transverse Section (T.S.): Cross-sectional slices taken perpendicular to the plant’s axis, allowing the study of tissue distribution (e.g., epidermis, cortex, vascular bundles). It helps identify plant growth patterns and differentiate monocot/dicot plants.

2. Longitudinal Section (L.S.): Slices taken parallel to the plant’s axis, showing cell elongation and differentiation, particularly in growing regions like apices.

3. Radial Longitudinal Section (R.L.S.): Taken along the plant's radius to study secondary growth, showing radial tissue arrangement and the formation of growth rings.

4. Tangential Longitudinal Section (T.L.S.): A slice taken parallel to the outer surface of the plant, focusing on the arrangement of outer tissues (e.g., phloem fibers) and growth ring analysis.