Photomicrography – digital capture of LM images; useful for colour and size reference.
Transmission electron microscopy (TEM) – high‑resolution view of ultrastructure; reveals granules, membrane detail.
Identifying the Cells
Use the following checklist when examining a slide or image:
Check overall size with a calibrated eyepiece micrometer.
Determine presence or absence of a nucleus.
If a nucleus is present, note its shape (round, lobed, indented).
Look for granules: colour (neutral, eosinophilic, basophilic) and distribution.
Assess cytoplasmic-to-nuclear ratio (high in lymphocytes, low in neutrophils).
Suggested Diagrams
Suggested diagram: Light‑microscope view of a peripheral blood smear showing RBCs, neutrophils, monocytes and lymphocytes.
Suggested diagram: Electron‑microscope cross‑section of a neutrophil highlighting azurophilic granules.
Drawing Tips for Examination
When asked to draw a cell, follow these steps:
Outline the overall shape (disc, round, lobed).
Place the nucleus correctly – centre for lymphocytes, lobed for neutrophils, indented for monocytes.
Add granules only where appropriate (neutrophils).
Indicate relative size using a scale bar or by comparing to an adjacent RBC.
Label each part clearly (e.g., “biconcave disc”, “multi‑lobed nucleus”).
Summary
Mastery of cell identification relies on recognising size, nuclear morphology and granule pattern across three levels of observation – light microscopy, photomicrography and electron microscopy. Practising with the comparison table and the drawing checklist will build confidence for A‑Level examinations.