This document provides information about blood collection and processing. It defines blood and its functions. It describes the physical characteristics of blood and its composition. It discusses the purposes of blood collection and the techniques used for vein puncture, capillary puncture, and arterial puncture. It also covers sample handling, centrifugation, and factors to consider to prevent hemolysis.

1. SUBJECTIVE ASSIGNMENT 2
COURSE NAME :UGC ACADEMIC WRITING
STUDENT NAME : AMJAD HUSSAIN A
EMAIL ID : amjadbio@gmail.com
STUDENT ID : 85c71980f30b11e9896a7b4b300b6493

2. COLLECTION AND
PROCESSING OF
BLOOD SPECIMEN
Mr. A. AMJAD HUSSAIN, M.Sc., M.Phil, DMLT
Assistant Professor
Department of Biochemistry
Islamiah College (Autonomous)

3. What is Blood?
Blood is a combination of plasma and cells that
circulate through the entire body. It is a
specialized bodily fluid that supplies essential
substances around the body, such as sugars,
oxygen, and hormones.

4. Physical Characteristics of Blood
• Thicker than water
• 8 % of total body weight
• Blood volume
» 70 mL/kg of body weight
» 5 - 6 liters in males
» 4 - 5 liters in females
• Temperature - 100.40F
• pH - 7.35 to 7.45

5. BLOOD COMPOSITION
Suspension of cells in plasma (carrier fluid)
45% Cells
55% Plasma

6. BLOOD FUNCTIONS
1. Respiratory
 Transport O2 from lungs to tissues
 Transport CO2 from tissues to lungs
2. Nutrition
 Transport “food” from gut to tissues
3. Excretory
 Transport waste from tissues to kidney (urea, uric acid)
4. Protective
 White blood cells , antibodies, antitoxins.
5. Regulatory
 regulate body temperature
 regulate pH through buffers
 coolant properties of water
 vasodilatation of surface vessels dump heat
 regulate water content of cells by interactions with dissolved ions and proteins
6. Body Temperature
 Water- high heat capacity, thermal conductivity, heat of vaporization
 Typical heat generation is 3000 kcal/day

7. PURPOSE OF BLOOD COLLECTION
• Analyzing and quantifying various biochemical parameters in the body like
blood sugar, cholesterol, uric acid, etc.
• Measurement and morphological assessment of blood components like red
blood cells,
• White blood cells and platelets.
• Culture and antibiotic sensitivity of blood in case of septicemia.
• Therapeutic purpose: removal of blood for treatment of high levels of iron
(as in Haemochromatosis, thalassemia, etc) or red blood cells ( as in
polycythemia)
• To collect blood for later uses, like blood donation.

8. Phlebotomy
Drawing or removing blood from the circulatory
system through a cut (incision) or puncture in order
to obtain a sample for analysis and diagnosis.

9. SITE OF COLLECTION
Vein Blood Collection
Capillary Blood Collection
Arterial Blood Collection

10. VEIN PUNCTURE

11.  A phlebotomist must have a professional, courteous, and understanding manner
in all contact with all patients.
 The first step to the collection is to positively identify the patient by two forms
of identification; ask the patient to state and spell his/her name and give you
his/her birth date. Check these against the requisition (paper or electronic).
 Check the requisition form for requested tests, other patient information and any
special draw requirements. Gather the tubes and supplies that you will need for
the draw.
 Wash your hands.
 Position the patient in a chair, or sitting or lying on a bed.
VENOUS BLOOD COLLECTION

12.  An elastic band/ tourniquet is tied around the arm/ site. The band /
tourniquet, retains blood within the arm and makes the veins more visible
 Select the vein from where sample is to be taken. Medial cubital vein is
most common vein but the sample can be taken from other sites also
 Cleanse the skin over the area with an antiseptic, in a circular motion,
beginning at the site and working outward.
 Ask the patient to make a fist.
 Grasp the patient’s arm firmly using your thumb to draw the skin taut and
anchor the vein.

13.  The needle is inserted into the vein keeping the beveled side of the needle
up. As soon as blood enters the hub of the needle, the blood is sucked into
vaccutainer. In case of syringe, the plunger is pulled back to allow filling of
the blood.
 The appropriate amount of blood is drawn and when it is about to
complete, remove the tourniquet.
 The needle is withdrawn from the vein.

14. After blood is drawn and the needle is removed, pressure is placed on the
puncture site with a cotton ball to stop bleeding, and a bandage is applied.
The patient or an assistant is instructed to apply firm pressure on the site for
sufficient time to stop the bleeding. After 2–3 minutes, the site should be
examined to check whether bleeding has stopped. Patients having high
Blood pressure or bleeding disorder or those taking anticoagulants may
require more time to stop the bleeding.

15. CAPILLARY PUNCTURE

16. CAPILLARY BLOOD COLLECTION
 The locations for capillary puncture is finger , ear lobe and heel.
 The best location for fingersticks are the 3rd (middle) and 4th (ring) fingers of
the non-dominant hand. Avoid sampling from tip and sides of the finger. Also,
avoid puncturing a finger that is cold or cyanotic, swollen, scarred, or covered
with a rash.
 Massage the finger toward the selected site prior to the puncture.
 Clean the skin with antiseptic.

17.  Using a sterile safety lancet, make a skin puncture just of the center of the
finger pad. The lancet should enter the finger perpendicularly other wise the
blood may run along finger pad ridges.
 Wipe away the first drop of blood, which tends to contain excess tissue fluid.
 Collect drops of blood into the collection tube/device by gentle pressure on the
finger. Avoid excessive pressure lest you may squeeze tissue fluid into the drop
of blood.
 Place a small gauze pad over the puncture site for a few minutes to stop the
bleeding.

18. ARTERIAL PUNCTURE

19. ARTERIAL BLOOD COLLECTION
 For arterial samples, the syringe and needle is held like a dart. The index
finger is used to locate the pulse. Then the needle is inserted at a 45 degree
angle, approximately 1 cm distal to (i.e. away from) the index finger, to
avoid contaminating the area where the needle enters the skin. The needle
is advanced into the artery until a blood flashback appears, then the syringe
is allowed to fall to the appropriate level. The syringe plunger should not be
pulled back. Finally the needle is withdrawn.
 A cotton swab is pressed to the puncture site and kept for about few
minutes. Note for any hematoma formation.

20. AREAS TO AVOID WHEN CHOOSING A SITE
FOR BLOOD DRAW
Certain areas are to be avoided when choosing a site for blood draw:
• Extensive scars from burns and surgery - it is difficult to puncture the scar tissue and
obtain a specimen.
• The upper extremity on the side of a previous mastectomy - test results may be
affected because of lymphedema.
• Hematoma - may cause erroneous test results. If another site is not available, collect
the specimen distal to the hematoma.
• Intravenous therapy (IV) / blood transfusions - fluid may dilute the specimen, so
collect from the opposite arm if possible.
• Cannula/fistula/heparin lock - hospitals have special policies regarding these devices.
In general, blood should not be drawn from an arm with a fistula or cannula without
consulting the attending physician.
• Edematous extremities - tissue fluid accumulation alters test results.

21. TECHNIQUES TO PREVENT HEMOLYSIS
(which can interfere with many tests)
• Mix all tubes with anticoagulant additives gently (vigorous shaking can cause hemolysis)
5-10 times.
• Avoid drawing blood from a hematoma; select another draw site.
• If using a needle and syringe, avoid drawing the plunger back too forcefully.
• Make sure the venipuncture site is dry before proceeding with draw.
• Avoid a probing, traumatic venipuncture.
• Avoid prolonged tourniquet application (no more than 2 minutes; less than 1 minute is
optimal).
• Avoid massaging, squeezing, or probing a site.
• Avoid excessive fist clenching.
• If blood flow into tube slows, adjust needle position to remain in the center of the lumen.

22. BLOOD SAMPLE HANDLING AND
PROCESSING
Pre-centrifugation Handling - The first critical step in the lab testing process,
after obtaining the sample, is the preparation of the blood samples. Specimen
integrity can be maintained by following some basic handling processes:
• Fill tubes to the stated draw volume to ensure the proper blood-to-additive
ratio. Allow the tubes to fill until the vacuum is exhausted and blood flow
ceases.
• Vaccutainer tubes should be stored at 4-25°C (39-77°F).
• Tubes should not be used beyond the designated expiration date.

23. • Mix all gel barrier and additive tubes by gentle inversion 5 to10 times
immediately after the draw. This assists in the clotting process. This also
assures homogenous mixing of the additives with the blood in all types of
additive tubes.
• Serum separator tubes should clot for a full 30 minutes in a vertical
position prior to centrifugation. Short clotting times can result in fibrin
formation, which may interfere with complete gel barrier formation.

24. Blood Sample Centrifugation – It is recommended that serum be physically
Separated from contact with cells as soon as possible, with a maximum time
limit of 2 hours from the time of collection. It is recommended that serum be
physically separated from contact with cells as soon as possible, with a
maximum time limit of 2 hours from the time of collection.
• Complete gel barrier formation (gel barrier tubes) is time, temperature and
G-force dependent. The uniformity of the barrier is time dependent; an
incomplete barrier could result from shortened centrifugation times.
• In general, for a horizontal, swing-bucket centrifuge, the recommended
spin time is 10 minutes. For a fixed-angle centrifuge, the recommended
spin time is 15 minutes.

25. • NOTE: Gel flow may be impeded if chilled before or after centrifugation.
• Tubes should remain closed at all times during the centrifugation process.
• Place the closed tubes in the centrifuge as a “balanced load” noting the
following:
Opposing tube holders must be identical and contain the same
cushion or none at all.
Opposing tube holders must be empty or loaded with equally
weighted samples (tubes of the same size and equal in fill).
If an odd number of samples is to be spun, fill a tube with water to
match the weight of the unpaired sample and place it across from this
sample.

26. CENTRIFUGE SAFETY
• Interference with an activated centrifuge by an impatient employee can result in
bodily injury in the form of direct trauma or aerosolization of hazardous droplets.
• Centrifuges must never be operated without a cover in place.
• Uncovered specimen tubes must not be centrifuged.
• Centrifuges must never be slowed down or stopped by grasping part(s) of the
device with your hand or by applying another object against the rotating equipment.
• Be sure the centrifuge is appropriately balanced before activating. If an abnormal
noise, vibration, or sound is noted while the centrifuge is in operation, immediately
stop the unit (turn off the switch) and check for a possible load imbalance.
• Clean the centrifuge daily with a disinfectant and paper towel. Broken tubes or
liquid spills must be cleaned immediately.