Blood smears

• Biological drawing


  Line pictures which show specific features that have been observed when the specimen was viewed
• Conventions for biological drawings

  • Drawing must have a title
  • Magnification must be recorded
  • Use HB pencil and good eraser
  • Draw on plain white paper
  • Use clear, single lines (no thick shading)
  • No shading
  • Drawing should take up as much space as possible
  • Draw well-defined structures
  • Drawing should have proper proportions
  • Label lines should not cross or have arrowheads, and should connect directly to the part being labelled
  • Label lines should be kept to one side of the drawing (in parallel to the top of the page) and drawn with a ruler
• Drawings of cells are typically made when visualizing cells at a higher magnification power, whereas plan drawings are typically made of tissues viewed under lower magnifications (individual cells are never drawn in a plan diagram)
• Blood smear


  A small amount of blood is spread on a glass microscope slide, stained and covered with a coverslip
• Red blood cells


  • No nuclei and a distinct biconcave shape
• White blood cells


  • Irregular shapes
  • Neutrophils have distinctive lobed nuclei and make up roughly 70% of all white blood cells
  • Lymphocytes have very large nuclei that nearly occupy the entire cell