3. objectives
⢠What is hemocytometer?
⢠What are the uses of hemocytometer?
⢠Principle of cell counting?
⢠What are the common source of error
during cell counting?
8. USES : -
⢠The use of haemocytometer counting
chamber in hematology lab for manual
counting of :
*White blood cells count.
*Red blood cells count.
*Platelets count.
11. NEUBAUERâS SLIDE
⢠Thick glass slide with two ruling area
on centre.
⢠Ruled area are separated by H-shape.
⢠Beyond the two vertical arm of
trough there are two raised
shoulder(ridge) which support cover
glass.
⢠lining is coated by shining metal or
rhodium.
12.
13.
14. ⢠Each scale is 3mm wide and 3mm long.
⢠Depth of the chamber is 0.1mm
⢠The whole scale is divided into 9 big
squares.
⢠Each square is 1mm long and 1mm wide.
20. ⢠Central square is divided into 25
medium sized square and are
separated by triple line
⢠The medium sized square are further
divided into 16 small square(tiny)
⢠The four corner and central square
are used for platelet and RBC count.
21.
22. ⢠Do not count cells touching
â Bottom line
â Right line
Counting Rule(L-shape)
26. Cover slip
⢠Special cover glass with smooth
surface and even thickness
⢠Thickness= 0.3, 0.4, 0.5 mm
⢠Length= 16x22mm, 22x23mm
27. The grid area of chamer = 9 mm2
.
The depth of chamber = 0.1 mm .
28. Hemocytometer Chamber
⢠Depth = 0.1 mm
⢠Grids = 9 mm2 .
â RBC use 5 small squares
in the center large square
â WBC use 4 corner large
squares
29. Principle
⢠Dilution of blood.
⢠Sampling of diluted suspension into
measured volume.
⢠Counting of cell in that volume.
30. Method : -
1: Clean the chamber and make sure
the central grid area of the
chamber and the special
haemocytometer cover glass are
completely clean and dry .
2: Attach the cover glass into position
over the grid area and press down
on each side until rainbow colours are
seen .
31.
32. 3: Dry underside of the chamber and
place on the microscope stage .
4: In WBCâs count using 10 x objective
with condenser iris closed to give a
good contrast.
5: In RBCâs and PLTs count using 40 x
objective with condenser iris in
center to give a good contrast .
33.
34. FOCUSING
⢠4X to see the general
formation of chamber.
⢠10X for WBC counting.
⢠40X for RBC/Plt.
counting
38. Sources of error
False high count False low count
⢠Improper mixing.
⢠Uneven distribution of cells.
⢠Error in pipetting.
⢠Error in calculation.
⢠Blood taken from area of
hemo concentration.
⢠Yeast, dirt and leucocyte
are counted as RBC.
⢠Blood diluted with tissue
fluid.
⢠Undue delay in counting of
cell.
⢠Clumping of cell.
⢠Uneven distribution of cell
⢠Faulty technique of
counting.
⢠Improperly standarized
counting chamber.