This document summarizes the components and use of a Neubauer hemocytometer for counting blood cells. The hemocytometer consists of a thick glass slide with an H-shaped groove containing scales for counting red and white blood cells under a cover slip. The slide is divided into squares to calculate cell concentrations in a known volume. Blood is diluted in pipettes before loading into the chamber. The document explains how to distinguish squares for different cell types, calculate cell volumes, count cells while avoiding double counting, and determine cell concentrations based on dilution factors and counts within the grids.

1. STUDY OF NEUBAUER’S
CHAMBER
BY: Dr.Sidra Qaiser

2. HEMOCYTOMETER
Hemo: blood
Cyto: cell
Meter: measurement/counter
Thus, it is an instrument used to count
the blood cells.

3. It includes:
a) Neubauer’s
slide
b) Cover slip
c) RBC pipette
d) WBC pipette

4. NEUBAUER’S SLIDE
It is the name given to a thick glass
slide. In the centre of the slide, there is
an H- shaped groove. On the two sides
of the central horizontal bar, there are
scales for counting the blood cells.
The depth of the scales is 1/10mm or
0.1mm.

5. Improved Neubauer Hemocytometer

8. NEUBAUER’S CHAMBER
Neubauer’s slide with a cover slip over it,
is called a Neubauer’s chamber.

10. • Each scale is 3mm wide and 3mm long.
• The whole scale is divided into 9 big
squares.
• Each square is 1mm long and 1mm
wide.

12. Hemocytometer
Chamber

13. Four
corner
squares
are meant
for WBC
counting.
Total = 64
small
squares
W
W
W
W

14. The central square is subdivided into
twenty five smaller squares and each of
these smaller squares is further
subdivided into sixteen smallest
squares.
These are meant for platelet and RBC
counting.

16. The platelets can be counted in all the
small squares of the central square.BUT
FOR CONVEINIENCE WE WILL
COUNT PLATELET IN THE CORNERS
SPECIFIED FOR RBCS.
(total of 80 smallest squares)

17. R R
R
R R

20. CALCULATION OF THE VOLUME OF WBC
SQUARES
Length of one small square = 1/4mm
Width of one small square = 1/4mm
Depth of one small square = 1/10mm
Volume of one small square
= 1/4 x 1/4 x 1/10
= 1/160mm³

21. CALCULATION OF VOLUME OF PLATELET
SQUARE
Length of one smaller square = 1/5 mm
Width of one smaller square = 1/5 mm
Depth of one smaller square = 1/10mm
Volume of one smaller square
= 1/5 x 1/5 x 1/10
= 1/250mm³

22. Each of the smaller squares is further
subdivided into sixteen smallest squares.
Length of one smallest square = 1/5 x 1/4
= 1/20mm
Width of one smallest square = 1/20mm
Depth of one smallest square = 1/10mm
Volume of one smallest square
= 1/20 x 1/20 x 1/10
= 1/4000mm³

23. Cell Counts by Hemocytometer

24. Counting Rule
• Do not count cells
touching
• Bottom line
• Right line
 This is to avoid
double counting.

27. DIFFERENCES BETWEEN RBC AND
WBC PIPETTE
RBC pipette WBC
pipette
1) It has a red bead It has a white
bead
2) It has
graduations upto
mark 101
It has
graduations upto
mark 11
3) Size of bulb is
larger
Size of bulb is
smaller
4) Size of lumen is Size of lumen is

28. RBC PIPETTE
WBC PIPETTE

30. DILUTION FACTORS
For CELL counting
Blood is filled till mark 0.5 and fluid is then
filled till mark 101.Both are thoroughly mixed.

33. For Platelet counting
1 part of blood is mixed in 100 parts of
Platelet fluid (Rees Ecker) , so dilution
factor for platelet counting is 100.

34. PLATELET COUNTING
Total no. of Cells in 80(5x16) smallest squares =
X
No. of Cells in one smallest square = X/80
Volume of one smallest square = 1/4000mm³
No. of Cells in 1/4000mm³ = X/80
No. of Cells in 1mm³ = X/80 x 4000
No. of Cells in 100 times diluted blood
= X/80 x 4000
No. of Cells in undiluted blood
= X/80 x 4000 x 100/mm³

37. • 40X for plateletcounting
FOCUSING

40. 40x magnification