1. November
8, 2015
PRACTICAL CELL BIOLOGY LAB 4
Cell counting
Introduction
Cell counts may be used to identify diseases and to monitor a person's
health. They can alert a doctor to an issue in a person's body and prompt a doctor
to perform appropriate tests. Many biological applications such as microbiology,
cell culture, blood work and many others that use cells require that we determine
cell concentration for our experiment.
Here are several examples for the need for cell counting:
In medicine, the concentration of various blood cells, such as red blood
cells and white blood cells, can give crucial information regarding the health
situation of a person.
Similarly, the concentration of bacteria in the blood or in other bodyfluids can
reveal information about the progress of an infectious disease and about the
degree of success ofthe immune system.
Studies that examine the growth rate of microorganisms (in other words:how
fast they divide to create new cells) require cell counting.
Measurements of cell viability, i.e. measuring and calculating the fraction of
dead and live cells from animal tissues such as liver, kidney……….etc, for
example cells exposed to poison.
2. November
8, 2015
PRACTICAL CELL BIOLOGY LAB 4
Methods of cell counting from fixed tissue on slide
1. By using square which mounted on ocular lens.
a) By using stage micrometer, find the length of one side of square on
ocular lens.
b) Find area of the square.
Area of a square is given by:
A = a2
Where a = length of side
c) Remove stage micrometer and place a slide on the stage of
microscope which you want to count number of cells on the slide.
d) Count cells within squares of the ocular lens
e) Find number of cells in one millimeter square.
3. November
8, 2015
PRACTICAL CELL BIOLOGY LAB 4
2. By using field of the microscope
a) By using stage micrometer, find the diameter of the field of
microscope.
b) Find area of the field.
Radius = diameter / 2
The area of a circle is π (Pi) times the Radius squared, which is written: A = π × r2
c) Remove stage micrometer and place a slide on the stage of
microscope which you want to count number of cells on the slide.
d) Count cells within field of the ocular lens.
e) Find number of cells in one millimeter square.
3. By using digital microscope
