College of Sciences
Medical Laboratory Science
7th Semester
Practical Advanced Hematology
Lab Report
7th Experiment
Platelets Count
Group Members: Mahab Abdulwahab
Wali Omed
Dyari Sardar
Hawbash Yassin
Siva Bakr
Sara Sherzad
Date of Test: December 11 /2024
CONTENTS
Introduction ……………………………………………..3
Aim of the Test …………………………………………3
Principle ………………………………………………...4
Materials Used ………………………………………....4
Procedure ……………………………………………….5
Result and Discussion ………………………………....6
Page 2 of 6
Introduction
Platelets, also known as thrombocytes, are small, colorless cell fragments in the
blood that are essential for clotting. They are produced in the bone marrow and
play an important role in stopping bleeding by forming clots and repairing
damaged blood vessels.
In order to perform their function in clotting and tissue regeneration, platelets in
despite their tiny size and absence of a nucleus—are very specialized and
physically complicated. Platelets have a lifespan of 7–10 days in the bloodstream.
After this period, they are removed and recycled by the spleen and liver.
Platelets in the blood are counted using a platelet counting test, that is a critical
diagnostic and monitoring tool in medicine and this common test is used to
identify or track diseases that impact platelets and is frequently a part of a
complete blood count (CBC).
Since Platelets play a vital role in blood clotting and wound healing, so their
levels directly affect a person’s risk of bleeding or clotting disorders.
There are several ways to count platelets, based on the tools used, the goal, and
the level of accuracy needed. Using certain methods, it may be carried out in labs
or point-of-care environments.
Aim of the Test
Platelet counting is used to determine the quantity of platelets in the blood in
order to evaluate and track a person's capacity to coagulate, stop excessive
bleeding, or identify disorders that lead to abnormal bleeding or clotting
tendencies. One of the most important diagnostic tools for assessing general
vascular and hematologic health.
Page 3 of 6
Principle
Manual platelet counting is a method used to estimate the number of platelets in
a blood sample. It involves diluting the blood with a specific diluent that lyses
red blood cells (RBCs) but preserves platelets and white blood cells (WBCs).
The platelets are then counted under a microscope using a counting chamber,
such as a Neubauer hemocytometer.
Materials Used
1. Blood Sample:
Fresh venous or capillary blood (EDTA anticoagulated preferred).
2. Test Tubes or Small Containers:
Used for mixing blood and diluting fluid.
3. Platelet Diluting Fluid:
The diluent lyses red blood cells (RBCs) while preserving and staining platelets
for visibility under the microscope:
o Ammonium Oxalate Solution (1%): Commonly used to lyse RBCs. We used this one
o Hayem’s Solution: Occasionally used for RBC and platelet counts.
o Rees and Ecker’s Diluting Fluid: Contains gentian violet to stain platelets.
o Toulidine Blue Solution: For platelet visualization in specific methods
4. Hemocytometer:
A precision-engineered counting chamber with a ruled grid used to count cells.
Used type ( Neubauer Hemocytometer).
5. Microscope:
Light microscope typically the 40x or 100x.
6. Micropipette or Capillary Pipette:
For accurate measurement of blood and diluting fluid volumes.
7. Cover Glass:
A high-quality, optically clear cover glass designed for use with
hemocytometers.
Page 4 of 6
Working Process
1. Collection of Blood Sample:
Collect a small volume of venous blood (preferably in an EDTA tube to
prevent clotting) or a capillary blood sample.
.
2. Dilution of Blood:
Use capillary or venous blood collected in an anticoagulant tube.
Ensure no clots are present in the sample.
Use 1% ammonium oxalate solution (or other suitable diluents).
Add 20 μL of blood to 1.98 mL of diluting fluid to achieve a 1:100
dilution. Mix gently to avoid lysing platelets.
3. Loading the Hemocytometer:
Secure a specialized cover glass on the hemocytometer's platform.
Using a micropipette, carefully fill the counting chamber by placing the pipette
tip at the edge of the cover glass.
Allow the chamber to fill by capillary action without overflowing.
Let the hemocytometer sit for 10–15 minutes in a humid chamber to allow
platelets to settle and become visible.
4. Microscope Observation:
Use a light microscope at 40x or 100x magnification.
Platelets appear as small, round, refractile particles. Ignore debris and artifacts.
Count platelets in the central large square of the hemocytometer grid, which
is divided into 25 smaller squares.
5. Calculation
6. Reporting:
Normal platelet count: 150,000–450,000 platelets/μL.
Results below or above the normal range indicate potential thrombocytopenia
or thrombocytosis.
Page 5 of 6
Result and Discussion
In our experiment that we performed we prepared our sample and stated to count
the platelets in central squares which we rich a number of 439000 per microliter
using the following equation:
Square A: 93
Square B: 88
Square C: 75 ∑ Squares: 93+ 88+ 75+ 87+ 96= 439
Square D: 87
Square E: 96
Total Number of Platelets: 439×1000 /μL =439000 /μL
The obtained result of 439000/μL of platelets in our experiment is considered a
normal physiologic raise in number since our friend lives in Suleimany and it's an
area of high altitude it's not an abnormal elevation and also there is no observed
pathologic Thrombocytosis symptoms or signs.
We also discussed that some of or group member have a problem in using
microscope and finding the central square so our good members in using the
microscope helped them and caused more time spending.
And also we didn’t depend on 100x counting since our microscopes lens are
contaminated and performed most of the counting on the 40x.
Page 6 of 6
