2. Blood
It is a specialized body fluid and comprises of four major components like
plasma, RBC, WBC and Platelets.
Whole blood - runs through the veins, arteries
Whole blood = 55% plasma + 45% Blood cells
About 7 to 8 percent of the total body weight is blood
pH of the blood ranges from 7.35-7.45
3. Collection of Blood
Materials required
Sterile syringe (preferably disposable one)
Cotton
Alcohol
Tourniquet
Sterile collection tube
EDTA coated collection tubes (if necessary)
Procedure
The area of injection or incision should be cleaned with alcohol.
The needle is inserted parallel to the vein and the tip directed into the lumen
along the longitudinal axis. When withdrawing blood from a vein, aspiration
should be slow, so the vessel does not collapse.
Blood should be collected in a sterile disposable syringe and stored properly.
4. Serum
It is neither a blood cell nor a clotting factor.
To define shortly, Blood serum is nothing but blood plasma with fibrinogens
removed.
Serum includes all proteins not used in blood clotting (coagulation) and all
the electrolytes, antibodies, antigens, hormones, and any exogenous
substances (e.g., drugs and microorganisms).
The study of serum is serology.
Serum is used in numerous diagnostic tests, as well as in blood typing.
After centrifugation, Coagulated blood (clotted blood) yields serum without
fibrinogen, although some clotting factors remain.
Serum = plasma - fibrinogens (and other clotting proteins)
5. Procedure
In general, the clotting process begins when a blood sample is collected from a
patient into collection tube.
A specimen collected in a blood collection tube with clot activator should be
inverted five times to facilitate the clotting process (If necessary).
Allow the blood to remain in the ambient temperature until the clot has formed.
Once the clot is formed, the specimen is ready for centrifugation.
When centrifuging specimens, it is very important to ensure that the centrifuge
is balanced properly.
The samples need to be centrifuged at 1100 rpm for 15 min and the supernatant
containing serum should be collected in a sterile tube for further analysis.
6. Plasma
It is the yellow liquid component of blood in which the blood cells in whole
blood are normally suspended.
It makes up about 55% of the total blood volume.
It is mostly water (93% by volume) and contains dissolved proteins, glucose,
clotting factors, mineral ions, hormones and carbon dioxide (plasma being
the main medium for excretory product transportation).
Blood plasma is prepared by spinning a tube of fresh blood containing an
anti-coagulant in a centrifuge tube until the blood cells fall to the bottom of
the tube.
The blood plasma is then poured or drawn off. Blood plasma has a density of
approximately 1025 kg/m3, or 1.025 kg/l.
Plasmapheresis is a medical therapy that involves blood plasma extraction,
treatment, and reintegration.
7. Procedure
The blood sample collected should be centrifuged at 900 g for 15 min at
room temperature.
Remove the tubes from the centrifuge and collect the plasma located on
the top of the blood and transfer to the appropriately labelled
microcentrifuge tubes.
After collecting the plasma, the samples were stored at -80°C
