Introduction to hematolgy

1. “Introduction to Hematology”
Sweta Tiwari
B.Sc (BTC)
Semester 6

3. Introduction
• Hematology is the branch of pathology related to the study,
diagnosis, treatment and prevention of diseases related to
blood.
• Hematology word is also taken from greek words “haima”
which means blood and “logia” which means suffering and
study.
• It also includes study of etiology.
• It involves treating diseases that affect the production of blood
and its components.

4. Clotting time
• In order for blood to clot, the enzyme thrombin must be
generated from the plasma in precursor prothrombin.
• Thrombin then converts soluble fibrinogen into insoluble
fibrin.
• Generation of thrombin involves the sequential activation of a
number of other plasma clotting factor, this process is also
being assisted by Ca++ and by factors released by platelets and
damaged tissues .

6. Bleeding time
• Bleeding time is actually defined as the time between the
incision and the natural stoppage of blood.
• Blood can be taken from either veins or ear lobe.
• Normal bleeding time is in between 1-9 minutes.

8. Total RBC count
• INTRODUCTION
• Blood cell counts are traditionally expressed as
number of cells per cubic milliliter of blood.
• To determine whether there are adequate no.
of cells in blood, a total RBC count is done.
• Normal RBC range in men is 4.7 to 6.1 million
cells per microliter and in women it is 4.2 to 5.4
million cells per microliter.
•

9. REQUIREMENTS
• RBC diluting pipette
• RBC diluting fluid
• Haemocytometer
• Blood sample

10. PROCEDURE
• Make an incision on the tip of disinfected middle finger
using a lancet.
• Draw the blood in RBC diluting pipette up to mark 0.5.
• Then draw RBC diluting fluid in the same pipette up to mark
101.
• Then fill the chamber of haemocytometer and observe it
under microscope.
CALCULATIONS
• RBC/mm3=4000/80 X 200
• 4000/80= volume from which the cells are counted.
• 200= dilution factor.

12. Total WBC count
• INTRODUCTION
• WBC are also called leukocytes, which are a very
important part of our immune system.
• they help in attacking viruses, bacteria and other
foreign agents invading our body.
• it is defined as the total no. of WBC per cubic
milliliter.
• There are mainly two types of leukocytes.

14.  REQUIREMENTS
• WBC diluting pipette
• WBC diluting fluid
• Haemocytometer
• Blood sample

15. PROCEDURE
• Make an incision on the tip of disinfected middle
finger using a lancet.
• Draw the blood in WBC diluting pipette up to mark
0.5.
• Then draw WBC diluting fluid in the same pipette
up to mark 11.
• Then fill the chamber of haemocytometer and
observe it under microscope

16.  CALCULATIONS
• Dilution factor=20
• Multiplication factor=50

17. What are blood types?
There are 3 alleles or genes for blood type: A,
B, & O. Since we have 2 genes, there are 6
possible combinations.

18. Making Blood smear!
• Three basic steps to make blood film:
• Preparation of blood smear.
• Fixation of blood smear.
• Staining of blood smear

19. Equipments:
•Spreaders
•Clean slides
•Applicator stick
wood
•Blood capillary tube
or micropipette 10
µL

20. Procedure:
• Fill a capillary tube three-quarter full with the anticoagulated specimen or a wooden
stick.
• Place a drop of blood, about 2 mm in diameter approximately an inch from the
frosted area of the slide.
• Place the slide on a flat surface, and hold the narrow side of the non frosted edge
between your left thumb and forefinger.
• With your right hand, place the smooth clean edge of a second (spreader) slide on the
specimen slide, just in front of the blood drop.
• Hold the spreader slide at a 30°/45° angle, and draw it back against the drop of blood.
• Allow the blood to spread almost to the edges of the slide.
• Push the spread forward with one light, smooth, and fluid motion. A thin film of
blood in the shape of a bullet with a feathered edge will remain on the slide.
• Label the frosted edge with patient name, ID# and date.