Cell Microscopy Lesson Objectives (L.O.) To calculate the mitotic index within a field of view 31 st January 2006 To be able to measure cells in interphase and compare with cells in cytokinesis

The Cell Cycle Interphase Prophase Metaphase Anaphase Telophase

Field of View Mitotic index = Number of cells in Mitosis Total number of cells ________________ Calculate Mitotic index for your slide Count how many cells in the different stages of mitosis 38/51 = 0.74

Measuring Cells The basic unit of measurement is the metre Larger units: Km – Kilometre When measuring cells we must go smaller; Millimetre (mm) 1/1000m 0.001m or Micrometre (µm) 1/1000,000m 0.000,001m or Nanometre (nm) 1/1,000,000,000m 0.000,000,001m or 10 -9

Calibration 2.Line up the divisions on the eyepiece graticule with those on the micrometre 1.Place the stage micrometre on the microscope stage 3. Work out the length of one eyepiece graticule in micrometres In this example: 3 eyepiece graticule units = 4 micrometer units = 4000μM Therefore, 1 eyepiece graticule unit = 4000/3 = 1333μM

Measure the size of a cell in interphase and a cell in cytokinesis (very end of telophase). Draw labelled diagrams of cells in the different stage of mitosis