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:
Neubauer’s slide
Cover slip
RBC pipette
WBC pipette

4. NEUBAUER’S SLIDE It is the name given to a thick glass slide
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/ = 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 pipette1)
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 smaller
Size of lumen is larger

28. RBC PIPETTE
WBC PIPETTE

30. DILUTION FACTORS For CELL counting Blood is filled till mark 0
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
= X x 32,000,000/mm³

37. FOCUSING
40X for plateletcounting

40. 40x magnification

41. THANKS