Measuring cell size

• Most organisms are multicellular and have cells that are specialised to do a particular job.
• Microscopes are needed to study cells in detail.
• To measure cell size, you must find out the distance measured for each division of the graticule.
• The graticule can be used to measure cells.
• The distance measured for each division of the graticule will be different for each objective.
• A glass slide with a scale etched on it, the stage micrometer is used to calibrate the eyepiece graticule of a microscope.
• Once the stage micrometer is calibrated, it can be used every time the microscope is used.
• To set an instrument or scale against a standard, the eyepiece graticule is calibrated.