How to Examine a
Blood Film
Reem Alsolami
Compound Microscope Parts
How to examine Blood film
Macroscopic Examination
e.g. Over all blurred smear is caused by increased
blood proteins in Multiple Myeloma
10x objective Examination
40x objective Examination
100x objective –oil Immersion Examination
Microscopic Examination
Microscope should be properly adjusted on the area of blood smear
will be examined.
The light from the illuminator should be properly centered.
Condenser should be placed all the way up.
Iris diaphragm must be opened
See the explaining video
10x objective Examination
Quick scanning of over all smear quality
Assess the distribution of the RBCs.
Assess WBC distribution
Most importantly to define the
EXAMINATION AREA
Large abnormal cells can be seen example:
Blast
Reactive lymphocytes
Unexpected parasites
Examination Area
40x objective (For WBC estimation)
40x objective examination
WBC Estimation
Count the WBC number regardless of there type in 10
fields
Use this equation:
Total number of counted WBC/ number of fields x
2000= WBC cells/ μL
• Remember μL-> x103 ; L-> x 109 /L
• e.g. 5000 WBC cells / µL-> 5 x103/µL 5 x 109 /L
Normal WBC Reference range : 5 x 103 - 10 x 103 / µL
100x objective-oil immersion Examination
• For Platelets estimation
• For RBC morphology evaluation
• For WBC differentiation
Platelets estimation
• Normal Size: 1-3 μm
• Irregular outlines
• Fine-violet granulation
(scattered or centralized)
• Giant platelets:
• Size: 4-5 μm
• Same features of morphology
Platelets estimation
Count platelet in 10 fields under 100x.
Use the following equation:
Total no. of Platelets/ field x 20,000 = cell/ μL
Normal range of platelets = 150,000 –350, 000 cell/ μL
RBC morphology and nucleated RBC examination and
RBC morphology
A. Evaluate RBC morphology based on their size(cytic), and colour
(chromic).
Normocytic Normochromic ( normal peripheral blood and some type
of leukaemia like the one associated with leukaemia.
-Size of normal RBC: 6.8-7.2 μm
-Central pallor, not vacuolated or granulated
Microcytic hypochromic (IDA, thalassemia)
Macrocytic normochromic ( Megaloblastic anaemia, and folic acid
deficiency).
1
2
3
RBC morphology
B. Report any abnormal RBC shapes
WBC Differential
PMN
Typical small
Lymphocyte
monocyte
Basophil
Eosinophil
12-14μm
9-12 µm
12-18μm
12-17μm
10-14μm
Multilobed(2-4)
nucleus
connected by
thin strands
.High N:C
ratio.
.Round
nucleus
.Round cell
.Chromatin
condensed
Nucleus
folded, or
kidney
shaped,
chromatin is
less dens than
lymphocytes.
Very fine
azurophilic
granules
Bilobed with
large redorange
granules.
Bilobed with
large dark blue
granules may
obscure the
nucleus
(48-70%)
(18-42%)
(1-10%)
(1-4%)
(0-2%)
Absolute WBC cell type Count
• Total count of leukocytes x one type of WBC =
Absolut count of this cell type
100
• The unit is dependent on the total leukocyte, for example
if the total WBC count is /L the result will be in /L , and if
it is /µL , the result of the Absolute will be /µL .
• Example
What is the absolute count of neutrophil?
How to write your report
• See the word document
• See future hematology teaching video