CELL COUNTING USING HAEMOCYTOMETER / HEMOCYTOMETER

Hemocytometer or Haemocytometer is a device used to count cells.Cell Counting using haemocytometer is a technique used to count cells in a given sample. A known volume of cell culture is counted using a haemocytometer and the total number of cells is calculated. Haemocytometer is a device that was originally used to count blood cells. But now it is also used to count many other types of cells. It consists of a thick glass microscope slide with a rectangular indentation that creates a chamber. This chamber is engraved with a laser-etched grid of perpendicular lines. The simplest dimension for us to use is the 1mm2 area when a special cover slip is placed over the haemocytometer.

Haemocytometer Calculation

The volume of the numbered squares is 0.1 mm3 (0.1 µl) and the average number of cells in one square must be multiplied by 104 and by a factor to correct for the dilution (if any) to calculate cells/ml.
Number of cells/ml = Average number of cells/grid x Dilution factor x 104.





Trypan blue is a vital stoluain used to selectively color dead tissues or cells blue. It is a diazo dye.
Live cells or tissues with intact cellmembranes are not coloured. Since cells are very selective in the compounds that pass through the membrane, in a viable cell Trypan blue is not absorbed; however, it traverses the membrane in a dead cell. Hence, dead cells are shown as a distinctive blue color under a microscope. Since live cells are excluded from staining, this staining method is also described as a Dye Exclusion Method.