4.6—Core Practical 7 - plant tissue microscopy

To investigate plant tissues, cut a very thin transverse stem section, stain it, mount it without trapped bubbles and observe it under a light microscope. Use a plan diagram to record the tissue arrangement.

Identify xylem vessels, phloem sieve tubes and sclerenchyma fibres from their staining, wall structure and position. Draw the overall distribution at low power; draw recognisable cells at higher power, with labels connected directly to visible features.

Toluidine blue can make xylem and sclerenchyma blue-green while phloem appears pink-purple, helping distinguish the vascular bundle before you compare the inner xylem with outer phloem.

A plan diagram shows position and pattern, not individual cell detail. Air bubbles, a thick section or a misleading section plane can look like tissues, so only label what the image supports.