WBC differential count
In the normal blood film, up to five different types of normal WBC can be
seen. They are Neutrophils (stab and polymorphs), Lymphocytes, Monocytes
In disease either the percent of normal WBC is disturbed, or/and abnormal
and immature WBC are seen in a peripheral blood films.
The object of differential WBC count is to determine the percentage of each
type of WBC from a stained blood film.
- Staining Racks.
- Dust free clean glass microscope slide.
- Spreader which should be a microscope slide and one corner removed
at each end.
- Leishman's stain.
- Emersion oil.
1- Place a drop of oil on a dry, well stained film and place a clean cover
glass on top. The oil should spread under the cover glass and cover the
tail and central part of the film.
2- Using the power 10 objective, select an area which is well stained and
3- Switch to power 40 objective.
4- Zero the differential counter.
5- Count all WBC seen in a single longitudinal direction, pressing the
button on the counter corresponding to type of WBC.
6- If you reach the end of the selected area and less than 100 WBCs are
counted, move the film one field down or up and continue counting in
another longitudinal strip in the opposite direction.
7- Stop counting when you hear the alarm on the counter. The total
number of WBCs counted should be 100.
8- Record the percentage of each type of WBC directly from the counter.
Note: if no counter is available, record your count on paper on groups of the
Differential white blood cells count (normal adult)
Absolute Values Percentage.
Neutrophil 2.0-7.0 x109/L 40-75 %
Lymphocytes 1.0-3.0 x109/L 20-45 %
Monocytes 0.2-1.0 x109/L 2-10 %
Eosinophil 0.02-0.5 x109/L 1-6 %
Basophile 0.02-0.1 x109/L 0-2 %