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.
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
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.
11.
12.
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.
18.
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.
21.
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.
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