This document discusses total leukocyte count (TLC), also known as the total white blood cell count. It provides the normal ranges for TLC across different age groups. Leukocytosis is defined as a TLC over 11,000/mm3 and can occur due to physiological or pathological factors. Leukopenia is a TLC below 4,000 cells/cu.mm and can be caused by various infections, bone marrow depression, or drugs. The document then describes the manual hemocytometer method for counting white blood cells using a Neubauer chamber, as well as an electronic method using automated analyzers.

1. TOTAL LEUCOCYTE COUNT
Dr. Shameera Begum

2. TOTAL LEUCOCYTE COUNT
 Number of white blood cells in 1 µl or
1 cubic mm of blood
 Normal range
Age group Cells / cu.mm
Adults 4000-11,000
At Birth 18,000 ± 8000
1 yr 6,000 - 15000
2 – 6 yr 5,000 - 15000
6-12yr 5000-13,000
Pregnancy Upto 15,000

3. LEUCOCYTOSIS
TLC > 11,000/MM3
Physiological
 At birth
 Pregnancy
 High temperature
 Severe pain
 Muscular exercise
Pathological
 Infections
 Malignancy like leukemia
 Severe haemorrhage

4. LEUCOPENIA
TLC < 4000 CELLS /CU.MM
 Bacterial infections(typhoid)
 Viral infection (Hepatitis, Influenza)
 Protozoal infection(Malaria)
 Megaloblastic anemia
 Bone marrow depression as in aplastic anemia,
drugs, radiation

5. METHODS
 Visual haemocytometer method
 Electronic method

6. HEMOCYTOMETER
 Hemo: blood
 Cyto: cell
 Meter: measurement/counter
It is an instrument used to count the blood cells.

7. SPECIMENS
 EDTA blood
 Capillary blood

8. REQUIREMENTS
 Microscope
 Hemocytometer
 WBC diluting fluid

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

10. 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.

13. NEUBAUER’S CHAMBER
 Neubauer’s slide with a cover slip over it, is
called a Neubauer’s chamber
 Four corner squares are meant for WBC
counting.
 Total = 64 small squares

14. WBC PIPETTE
 It has a white bead
 It has graduations upto mark 11

15. WBC (TURK’S) DILUTING FLUID:
It is prepared as follows:
 a) Glacial acetic acid: 2.0 ml
 b) 1 % (w/v) gentian violet: 1.0 ml
 c) Distilled water: 97 ml

16. PRINCIPLE
 The glacial acetic acid lyses the red cells while
the gentian violet slightly stains the nuclei of
the leukocytes.
 The blood specimen is diluted 1:20 in a WBC
pipette with the diluting fluid.
 The cells are counted under low power of the
micro scope by using a counting chamber.
 The number of cells in undiluted blood are
reported per cu mm (µl) of whole blood

17. PROCEDURE
 Draw blood up to 0.5 mark of a WBC pipette.
 Carefully, wipe excess blood outside the pipette
by using cotton.
 Draw diluting fluid up to 11 mark.
 Mix the contents in the pipette and after five
minutes by discarding few drops, fill the
counting chamber and allow the cells to settle
for two to three minutes.

19. FOCUSING
 4X to see the general formation
of slide.
 10X for WBC counting

20. COUNTING RULE
 Do not count cells touching
 Bottom line
 Right line
 This is to avoid double counting.

22. DILUTION FACTOR
0.5 part of blood is mixed in 10 parts of fluid
So, 1 part of blood is in 20 parts of fluid
Thus, dilution factor for WBC counting is 20.

23. CALCULATION OF THE VOLUME OF
WBC SQUARES

24. No. of cells counted x dilution
WBC count (per cubic mm) = ----------------------------------------
Volume of chamber
N x 20
= ---------------
4 x 0.1
= N x 50 cells / cubic mm

25. ELETRONIC METHOD
 Coulter – Automated haemanalyser
Advantages
Easy and rapid method
Time saving
Very large number of cells are counted rapidly
High level of precision
Disadvantages
Costly
Calibration error
Nucleated RBCs are counted as leucocytes
Platelet clumps counted as leucocytes

26. OTHER USES OF NEUBAUER CHAMBER
 RBC count
 Platelet count
 CSF cell count
 Sperm count

27. AUTOMATED HAEM ANALYZER

30. Thank You