SPECIMEN COLLECTION
1
BLOOD
2
BLOOD SPECIMEN COLLECTION, PREPARATION AND
HANDLING
I.
SPECIMEN COLLECTION
A. Introduction
As members of the health care team, phlebotomist must recognize that their
primary responsibility is to the patient's health and well being. It is important
for the phlebotomist to maintain a professional attitude and neat appearance.
Good interpersonal skills help establish patient trust and alleviate
apprehension.
Specimen collection by venipuncture or skin puncture involves a series of
steps that must receive careful consideration to ensure the best possible
specimen for laboratory analysis. It is the responsibility of the phlebotomist
to have a thorough understanding of and to abide by these guidelines to avoid
the many potential sources of error.
B. Preparation
Prior to each collection, review the laboratory's specimen requirement. Note
the proper specimen to be collected, the amount, the procedure, the collection
materials, and the storage and handling requirements.
Provide the patient in advance with appropriate collection instructions and
information on fasting, diet, and medication restrictions when necessary.
Confirm identification in the presence of the patient. Process and store the
specimen as required. During specimen collection, preparation, and
submission, there is a much greater possibility of critical error than during
actual testing or examination of the specimen. Errors in storage and handling
compromise the integrity of the specimen and, thus, the test results. Test
results are only as good as the specimen collected.
C. Patient Instructions and Preparation
Procedures with needles induce stress and anxiety in many patients, and
emotional stress can affect certain laboratory test values. The phlebotomist
therefore should do his or her best to relieve such apprehension. Communicate
with the patient in a calm, professional, and reassuring manner. Gain the
patient's confidence by soliciting his or her cooperation. Reassure the patient
that although the puncture itself maybe slightly painful, it will be over quickly.
Never deceive the patient by saying the procedure will not hurt.
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The patient should be comfortable with his or her arm easily accessible and
fully extended. Patients in bed should be instructed to lie on their backs, if
possible. The phlebotomist should seek assistance if patient movement is
anticipated. If additional support is needed, a pillow may be placed under the
elbow of the arm from which the specimen is to be drawn. Ambulatory
patients should be seated comfortable in a chair, preferably one with an
interlocking armrest for firm support. The phlebotomist should position
himself or herself in front of the chair to protect the patient from falling
forward if fainting occurs. The arm should be extended downward below
shoulder level, and the opposite fist should be placed under the elbow for
support. Please refer to the test directory section to note any specific dietary
requirements or special restrictions for the ordered test.
D. Blood Specimen Containers
The accuracy of any specimen depends upon the quality of the specimen.
Materials for proper specimen collection and transport are supplied by the
Altoona Regional Health System Laboratory.
Specimen Identification
According to the National Committee for Clinical Laboratory Standards
(NCCLS) H3-A4, Vol. ll. No.10, proper identification of specimens is extremely
important. "All tubes should be labeled immediately after the blood specimen
has been drawn. The completed label must be attached to each tube before
leaving the side of the patient, and the identity of the person who drew the
blood must be on the label". This procedure eliminates the possibility of mixing
up the blood specimens. Unidentified samples will not be tested; therefore,
clearly label each specimen with the patient's full name, date and time collected,
test name and phlebotomist initials. Information on preprinted computer labels
must be verified.
Anticoagulants and Preservatives:
To ensure accurate test results, all tubes containing an anticoagulant or
preservative must be allowed to fill completely. Attempts to force more
blood into the tube by exerting pressure will result in damage to the red cells
(hemolysis). If the vacuum tube is not filling properly, and you are certain
that you have entered the vein properly, substitute another tube. It is
important to be certain that a tube is filled in order to avoid spurious results
due to an inappropriate anticoagulant to specimen ratio. A partially filled
collection tube may be acceptable. If a completely filled tube cannot be
obtained, contact the lab to determine specimen acceptability before releasing
the patient.
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Vacuum Tubes Containing Anticoagulants: When using vacuum tubes
containing anticoagulants and preservatives:
1. Tap the tube gently at a point just below the stopper to release any additive
adhering to the tube or stopper
2. Permit the tube to fill completely to ensure the proper ratio of blood additive
3. To ensure adequate mixing of blood with anticoagulant or preservative, use a
slow rolling wrist motion to invert the tube gently EIGHT times. Rapid wrist
motion or vigorous shaking contributes either to small clot formation or
hemolysis and fails to initiate proper mixing action
4. Check to see that all preservative or anticoagulant is dissolved. If any
preservative is visible, continue inverting the tube slowly until the powder is
dissolved.
Vacuum Tubes Without Anticoagulants: When using vacuum tubes containing no
anticoagulants or preservative:
1. Permit the tube to fill completely
2. Let the specimen stand for a minimum of 30 minutes and not longer than 45 minutes
prior to centrifugation. This allows time for the clot to form. If the specimen is
allowed to stand for longer than 45 minutes, chemical activity and degeneration of the
cells within the tube will take place, and test results will be altered as a consequence.
3. Centrifuge the specimen at the end of the 30 to 45 minute period in strict accordance
with the manufacturer's instructions for speed and duration of centrifugation. Note:
Some tubes have clot activators and the clotting time may be less. Please check the
package insert.
4. The Gold top tube (Hemogard closure) with clot activator is to be inverted (mixed)
FIVE Times.
THE ORDER OF DRAW
According to the National Committee for Clinical Laboratory Standards (NCCLS)
document H3-A4, "Procedures for the Collection of Diagnostic Blood Specimens by
Venipuncture," the order in which tubes should by filled is as follows:
1.
2.
3.
4.
5.
6.
7.
Blood culture tube (yellow top or blood culture bottles)
Plain tube, non-additive (red top) without clot activator, must check tube
Coagulation tube (blue top)
Gel separator (speckled or tiger top) without clot activator, must check tube
Heparin tube (green top)
EDTA tube (lavender top)
Plain tube (gold top) gel separator with clot activator
Because of the safety risks that accompany glass specimen tubes, infection control and
epidemiology experts recommend the use of plastic tubes.
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However, since plastic does not activate clotting, like glass does, red-top tubes must
contain a clot activator if they are to be used for serum testing. As a result the order in
which tubes are collected must take into consideration that plastic red tops, which contain
clot activators, are tubes with an additive and should not occupy the same place in the
order of draw as glass red tops without clot activators.
The risk of drawing plastic red tops first in the order is that, during the tube exchange, the
clot activator can carry over into the next tube. If the next tube is sodium citrate (blue
top) for coagulation testing, the clot activator can alter the results. Therefore if using
plastic tubes, the red top should be drawn after the blue top. If no blue top is drawn, the
plastic red top can precede a heparin (green) or EDTA (lavender) tube without concern
for carryover. The current thinking is that any carryover of the clot activator into tubes
other than blue tops is irrelevant. It is thought that the minute amount of clot activator
will be consumed by the excess heparin or EDTA and will not compromise their ability
to anticoagulate the specimen. By contrast, carryover of a clot activator into sodium
citrate (blue top) can consume clotting factors and result in prolonged clotting times even
though the specimen will still be anticoagulated
As a reminder, the NCCLS no longer recommends that a discard tube be drawn prior to a
blue top if the blue top is being used for routine coagulation testing, i.e., protime or PTT.
However, if factor assays are to be tested, a discard tube is recommended. Therefore, if
a physician orders routine chemistries, coagulation studies, and a CBC, the order of draw
if using a plastic red top is as follows:
1. Blue top
2. Red top
3. Lavender top
If a glass red top is used, the order is:
1. Red top
2. Blue top
3. Lavender top
Finally, heparinized tubes (green tops) should never be filled after an EDTA tube
(lavender top) if the heparin tube will be tested for potassium. Because EDTA
contains potassium salts, any carryover of EDTA into a heparin tube can result in falsely
elevated levels of potassium.
NCCLS bases the order of draw on well-researched evidence. Yet it remains
phlebotomy's best-kept secret. By reinforcing the principles of sound blood collection
practices through repetition and education, however, phlebotomists and their supervisors
can minimize this frequently committed preanalytical error and maintain the specimen
integrity that is essential to accurate results and quality care.
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VACUTAINER INFORMATION
Always purchase single use safety devices when performing phlebotomy procedures.
YELLOW STOPPER
Sterile collection of anticoagulated specimen used for microbiology studies (blood
cultures) SPS(sodium polyanetholesulfonate) in 2.5 ml of sodium chloride for difficult
venipunctures, pediatric or nursery patients. Use two for one set of blood cultures. Send
whole blood in original tube
BAC T/ALERT 40 ML STANDARD AEROBIC/F BLUE CAP
This is a blood culture bottle. Draw the blue cap aerobic culture 1st
BAC T/ALERT 40 ML STANDARD ANAEROBIC/F PURPLE CAP
This is a blood culture bottle. Draw the purple cap anaerobic culture 2nd
(1 SET EQUALS 1 BLUE CAP (AEROBIC) AND 1 PURPLE CAP (ANAEROBIC)
RED STOPPER
This is a tube that contains no anticoagulant or preservative. The clotted specimen will
yield a serum sample. For Blood Bank tests, please submit in original tubes. All other
tests, serum must be separated from cells within 45 minutes of venipuncture. Send serum
in a plastic transfer tube.
GOLD STOPPER TUBE OR MARBLED RED/GRAY
Contains clot activator and gel for separating serum from cells, but no anticoagulant.
The clotted specimen will yield a serum sample. Maybe used for assays requiring serum
unless otherwise stated. Centrifuge tube to separate serum from cells within 45 minutes
of venipuncture. Serum can be sent in original tube.
BLUE STOPPER (LIGHT)
Contains sodium citrate. Sodium citrate yields a plasma sample. Send plasma from a
centrifuged sample in a plastic transfer tube labeled "Plasma, Sodium Citrate."
If submitted immediately send whole blood in the original blue-stopper tube.
GREEN STOPPER (MINT GREEN)
Contains lithium heparin and a PST gel separator. Lithium heparin will yield a plasma
sample. Plasma must be separated from the cells within 45 minutes of venipuncture.
Centrifuge tube to separate the cells from the plasma and send in the original tube.
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LAVENDER STOPPER (PURPLE TOP)
Contains liquid K3 EDTA. This anticoagulant yields plasma or whole blood. Send whole
blood in the original lavender stopper tube and plasma in a plastic transfer tube labeled
"Plasma, EDTA"
GRAY STOPPER
Contains Sodium Fluoride and Potassium Oxalate. These anticoagulants yield plasma or
whole blood. Send plasma in a plastic transfer tube labeled "Plasma Sodium Fluoride".
Send whole blood in the original gray stopper tube.
ROYAL BLUE STOPPER TUBE
May contain sodium heparin, Na2EDTA or no anticoagulant. Used for trace elements,
toxicology and nutrient determinations. Send whole blood in the original royal blue
stopper tube.
BROWN STOPPER TUBES
Contains EDTA (Na2). Send whole blood in the original brown stopper tube.
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SELECTING APPROPRIATE COLLECTION TUBES
Stopper
Color
Gold/Marbled Gray
Gel Separator (SST)
Tube
Code
GLD/
MR
Light Green
Gel Separator (PST)
LGR
Red
R
Additive
Laboratory Use
No anticoagulant
Contains a clot
activator and gel for
separating serum
from cells.
Tube is to be gently
inverted (mixed) 5
times immediately
after collection
SERUM
SST Brand Tube for serum
determinations in chemistry.
Tube inversions to ensure mixing
of clot activator within 45
minutes of collection.
Refrigerate Specimens-send in
original tube
Frozen Specimens-transfer
serum to plastic container marked
"Serum"
NEVER FREEZE A SST TUBE
HEPARINZED PLASMA
PST Brand Tube for plasma
determinations. Tube inversion to
prevent clotting. Centrifuge
within 45 minutes of collection.
Refrigerate specimens - send in
the original tube.
Frozen Specimens - transfer
plasma to a plastic transfer tube
marked "Plasma Lithium
Heparin".
NEVER FREEZE A PST TUBE
Lithium heparin
anticoagulant and
gel for plasma
separation.
Tube is to be gently
inverted (mixed) 8
times immediately
after collection.
Note: Sodium
Heparin should not
be used for
Electrolyte
determination.
No Additive
No inversions
(mixing) necessary.
Clot activator
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SERUM OR CLOTTED
WHOLE BLOOD
All other tests
(serology/chemistry) centrifuge
within 45 minutes of collection.
Transfer serum to a plastic
transfer tube marked "Serum".
SELECTION APROPRIATE BLOOD COLLECTION
TUBE (CONTINUED)
Stopper
Color
Lavender
Tube
Code
LV
Additive
Laboratory Use
Liquid K3EDTA or
Freeze-dried
NA2EDTA
Anticoagulant
Tube is to be gently
inverted (mixed) 8
times immediately
after collection
EDTA WHOLE BLOOD OR
PLASMA
For whole blood hematology
determinations. Tube inversion
prevents clotting.
Send whole blood in original
tube.
For plasma specimen, centrifuge
within 45 minutes of collection.
Transfer plasma to a plastic tube
marked "Plasma, EDTA"
CITRATED PLASMA
For coagulation determinations.
Tube inversions prevent clotting.
Send Whole blood in the original
tube.
For plasma specimen, centrifuge
within 45 minutes of collection.
Transfer plasma to plastic tube
marked "Plasma, sodium citrate"
NOTE: This tube must be
completely filled to yield
accurate results. Tubes not
completely filled will be rejected.
Light Blue
LBL
Sodium Citrate
Anticoagulant
Tube is to be gently
inverted (mixed) 8
times immediately
after collection.
Yellow SPS
SPS
Sodium
polyanetholesulfonate
(STS)
Anticoagulant
Tube is to be gently
inverted (mixed) 8
times immediately
after collection
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SPS WHOLE BLOOD OR
BODY FLUID
For blood culture specimen
collections in microbiology. Tube
inversions prevent clotting.
Specimen should be submitted in
original tube.
Refer to microbiology specimen
collection section for special
collection guidelines.
SELECTING APPROPRIATE COLLECTION TUBES
CONTINUED
Stopper
Color
BAC T/ALERT
Blue Cap
Tube
Additive
Code
BACT BAC T/ALERT
Standard Aerobic
40 ml blood culture
bottle.
BAC T/ALERT
Purple Cap
BACT BAC T/ALERT
Standard Anaerobic
40 ml blood culture
bottle.
Gray
GRA
Sodium Fluoride or
Potassium Oxalate
Tube is to be gently
inverted (mixed) 8
times immediately
after collection
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Laboratory Use
AEROBIC BLOOD CULTURE
BOTTLE WHOLE BLOOD
Sterile collection required for
Microbiology blood culture.
Specimen should be submitted in
original bottle.
Refer to microbiology specimen
collection section for special
collection guidelines.
1 BLOOD CULTURE SET
EQUALS 1 BLUE CAP
(AEROBIC) AND 1 PURPLE
CAP (ANAEROBIC ) BOTTLE.
ANAEROBIC BLOOD
CULTURE BOTTLE WHOLE
BLOOD
Sterile anaerobic collection required
for Microbiology Blood Culture.
Specimen should be submitted in
original bottle.
Refer to microbiology specimen
collection section for special
collection guidelines.
1 BLOOD CULTURE SET
EQUALS 1 BLUE CAP
(AEROBIC) AND 1 PURPLE
CAP (ANAEROBIC) BOTTLE
SODIUM FLUORIDE WHOLE
BLOOD OR PLASMA
Tube inversion to prevent clotting.
Centrifuge within 45 minutes of
collection.
Send whole blood in original
tube.
SELECTING APPROPRIATE COLLECTION TUBES
CONTINUED
Stopper
Color
Dark Green
Royal Blue
Large yellow
Tube
Code
Additive
DGR
Sodium Heparin,
Lithium Heparin or
Ammonium Heparin
Anticoagulant.
Tube is to be gently
inverted (mixed) 8
times immediately
after collection.
Note: Sodium
Heparin should not
be used for
Electrolyte
determinations
Laboratory Use
HEPARINZED PLASMA
For plasma determinations in
chemistry. Tube inversions
prevent clotting.
Send whole blood in original
tube.
For plasma specimen, centrifuge
within 45 minutes of collection,
transfer plasma to a plastic tube
marked "Plasma Sodium
Heparin."
Red stripe- no
HEPARINIZED WHOLE
additive
BLOOD
Lavender stripeFor trace element, toxicology and
Sodium-EDTA
nutrient determinations. Special
Anticoagulant
stopper formulation offers the
Tube is to be gently lowest verified levels of trace
elements available.
inverted (mixed) 8
Send in the original tube
times immediately
after collection
Tissue Typing - Not to be used for Blood Cultures
ACD A or ACD B
RBL
E. Blood Specimen Collection from a line
Please refer to the Altoona Regional Health System’s procedures regarding
collection of blood culture samples from a line.
F. Collection Errors
Careful attention to routine procedures can eliminate most of the errors
outlined in this section. The complete blood collection system and other
collection materials provided by the laboratory can maintain the integrity of
the specimen only when they are used in strict accordance with the instructions
provided.
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General Specimen Collection Errors: Some of the common errors affecting
all types of specimens include:
Errors in venipuncture preparation:
1. Failure to label a specimen correctly and to provide pertinent information.
All specimens must be properly labeled in the presence of the patient.
2. Failure to check patient adherence to dietary restrictions before drawing.
3. Failure to calm patient prior to blood collection.
4. Use of improper equipment and supplies, i.e. incorrect container for
appropriate specimen preservation.
Errors in Venipuncture procedure:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Failure to dry site completely after cleansing.
Inserting needle bevel side down.
Use of a needle that has too small of a bore, causing hemolysis.
Prolonged tourniquet application.
Wrong order of tube draw.
Failure to mix blood collected in additive containing tubes immediately.
Pulling on a syringe plunger too forcefully.
Failure to release tourniquet prior to needle withdrawal.
Venipuncture in an unacceptable area: Avoid areas with hematomas,
burns, scars, or swelling. Avoid the side on which a mastectomy was
performed. If there is an IV infusion, whenever possible, blood should be
collected from the opposite arm or from a site below the IV. Please refer
to the Altoona Regional Health System’s procedures regarding collection
of specimens in the presence of an IV.
Errors after venipuncture completion:
1.
2.
3.
4.
5.
6.
Failure to apply pressure to venipuncture site.
Vigorous shaking of anticoagulated specimens
Forcing blood through a syringe needle into tube.
Mislabeling of tubes.
Failure to use the correct container for appropriate specimen preservation.
Failure to tighten specimen container lids, resulting in leakage and/or
contamination of specimens.
7. Insufficient quantity of specimen to run test or QNS (quantity not
sufficient).
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II.
SPECIMEN PREPARATION
A. Preparing Serum
Serum Preparation from Red Stopper Tube: Follow the steps below when
Preparing a serum specimen for submission.
1. Draw whole blood in an amount 2 and 1/2 times the required volume of serum
so that the expected amount of serum can be obtained. EXAMPLE: A 10 ml
red stopper rube will yield approximately 4 ml of serum after clotting and
centrifuging.
2. Place the collection tube in the upright position in a test tube rack, and allow
the blood to clot at room temperature for no longer than 30-45 minutes.
3. As soon as possible after a clot has formed, insert the tube in the centrifuge,
stopper end up. Operate the centrifuge for 10-15 minutes at the speed
recommended by the manufacturer. Do not allow prolonged centrifugation
as this may cause hemolysis. When using a bench top centrifuge, employ a
balance tube of the same type containing an equivalent volume of water. The
tube stopper should remain.
4. Turn the centrifuge off and allow it to come to a complete stop. Do not stop it
by hand or brake. Remove the tube carefully without disturbing the contents.
5. Remove the stopper and carefully aspirate most of the serum from the cells
using a separate disposable Pasteur pipette for each tube. Place the tip of the
pipette against the side of the tube, approximately 1/4 inch above the cell layer.
Do not disturb the cell layer or carry any cells over into the pipette. If
cells do enter the pipette, re-centrifuge the entire specimen.
6. Transfer the serum from the pipette into the plastic transfer tube. Inspect the
serum for signs of hemolysis and turbidity by holding it up to the light. Be
sure to provide the laboratory with the amount of serum specified.
7. Label the tube carefully and clearly with all pertinent information (refer to the
specimen identification section). NEVER LEAVE THE PATIENTS
BEDSIDE BEFORE PROPERLY LABELING THE SPECIMEN. Unless
otherwise indicated, serum samples should be refrigerated until they are sent to
the laboratory. When multiple tests requiring frozen serum are ordered, a
plastic transfer tube should be prepared for EACH test.
8. When frozen serum is required, place the plastic transfer tube(s) immediately
in the freezer. A separate frozen sample must be submitted for each test
requiring a frozen specimen.
Serum Preparation from Serum-Separator (SST) Tubes: Serum separator (Gold or
Marble red/gray stopper) tubes contain clot activator and gel for separating serum
From cells but include no anticoagulant. Adhere to the following steps when
Using a serum-separator tube.
1. Draw whole blood in an amount 2 and 1/2 times the required volume of serum
so that a sufficient amount of serum can be obtained. EXAMPLE: A 10 ml
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2.
3.
4.
5.
6.
7.
8.
Marble top tube will yield approximately 4 ml of serum after clotting and
centrifuging.
Gently invert the serum-separator tube five times to mix the clot activator and
blood.
Place the collection tube in the upright position in a test tube rack and allow
the blood to clot a room temperature for no longer than 30-45 minutes. Clots
will usually form in 20-30 minutes.
As soon as possible after a clot has formed, insert the tube in the centrifuge,
stopper end up. Operate the centrifuge for 10-15 minutes at the speed
recommended by the manufacturer. Do not allow prolonged centrifugation
as this may cause hemolysis. When using a bench top centrifuge, employ a
balance tube of the same type containing an equivalent volume of water. The
tube stopper should remain on the tube.
Turn the centrifuge off and allow it to come to a complete stop. Do not stop it
by hand or use a brake. Remove the tube carefully without disturbing the
contents. Inspect the barrier gel to ensure that it has sealed the serum from the
packed cells. Also examine the serum for signs of hemolysis and turbidity by
holding it up to the light. Be sure to provide the laboratory with the volume
of serum specified.
Label the tube carefully and clearly with all pertinent information (refer to the
specimen identification section). NEVER LEAVE THE PATIENTS
BEDSIDE BEFORE PROPERLY LABELING THE SPECIMEN.
If a frozen specimen is not required, it is not necessary to transfer serum to a
plastic transport tube.
When frozen serum is required, always transfer the serum (using a disposal
pipette) into a separate, clearly labeled plastic transfer tube. Place the plastic
transfer tube(s) immediately in the freezer. Never freeze a glass serumseparator tube. A separate frozen sample must be submitted for each test
requiring a frozen specimen.
B. Preparing Plasma
Plasma Preparation from a Plasma Separator (PST) Tube: When plasma is
Collected in a PST tube the following steps should be followed:
1. Always use the proper tube for tests requiring a special anticoagulant
(i.e. EDTA, heparin, sodium citrate, etc.)
2. Tap the tube gently to release additive adhering to the tube or stopper
diaphragm.
3. Permit the tube to fill completely. Failure to fill the tube will cause an
improper blood-to-anticoagulant ratio and yield questionable tests
results.
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4. To avoid clotting, mix the blood with the anticoagulant or preservative
immediately after drawing each sample. To ensure adequate mixing, slowly
invert the tube five to six times using a gentle wrist rotation motion.
5. Immediately centrifuge the specimen for 5-10 minutes. Do not remove the
stopper.
6. Turn the centrifuge off and allow it to come to a complete stop. Do not stop
by hand or use a brake. Remove the tube carefully without disturbing the
contents.
7. Make sure the tube is clearly labeled with all pertinent information (refer to
the specimen identification section) NEVER LEAVE THE PATIENTS
BEDSIDE BEFORE PROPERLY LABELING THE SPECIMEN.
8. If a frozen specimen is not required, it is not necessary to transfer plasma to a
plastic transport tube.
9. When frozen plasma is required, always transfer the plasma (using a
disposable pipette) into a separate properly labeled plastic transfer tube. Be
certain to mark the tube as to the contents (Example: "Plasma, lithium
heparin"). Place the plastic transfer tube(s) in the freezer. Never freeze a
glass or plastic plasma separator tube. A separate frozen sample must be
submitted for each test requiring a frozen specimen.
Plasma Preparation from Non-SST Tubes: Follow the steps below the prepare
plasma from all anticoagulated tubes that do not contain SST gel.
1. Always use the proper tube for tests requiring a special anticoagulant (i.e.
EDTA, heparin, sodium citrate, etc.) or preservative.
2. Tap the tube gently to release additive adhering to the tube or stopper
diaphragm.
3. Permit the tube to fill completely. Failure to fill the tube will cause an
improper blood-to-anticoagulant ratio and yield questionable test results.
4. To avoid clotting, mix the blood with the anticoagulant or preservative
immediately after drawing each sample. To ensure adequate mixing, slowly
invert the tube five to six times using a gentle wrist rotation motion.
5. Immediately centrifuge the specimen for 5-10 minutes. Do not remove the
stopper.
6. Turn the centrifuge off and allow it to come to a complete stop. Do not stop it
by hand or brake. Remove the tube carefully without disturbing the contents.
7. Remove the stopper and carefully aspirate plasma using a separate disposable
Pasteur pipette for each tube. Place the tip of the pipette against the side of
the tube, approximately 1/4 inch above the cell layer. Do not disturb the cell
layer or carry any cells over into the pipette. If the cell layer is disturbed,
the specimen must be recentrifuged. Do not pour off; use the transfer
pipette.
8. Transfer the plasma from the pipette into the transfer tube. Be sure to provide
the laboratory with the amount of plasma specified.
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9. Label all transfer tubes clearly and carefully with all required information.
All tubes should also be marked as to their content (Example: "Plasma,
sodium citrate").
10. When frozen plasma is required, place plastic transfer tube(s) immediately
into the freezer. A separate frozen sample must be submitted for each test
requiring a frozen specimen.
C. Preparation Errors
Serum Preparation Errors:
1. Failure to separate serum from red cells within 30-45 minutes of collection.
2. Hemolysis: Red blood cells broken down and components spilled into serum
(see below).
3. Lipemia: Cloudy or milky serum sometimes due to the patient's diet.
4. Failure to allow complete clotting of the specimen prior to centrifugation.
Plasma Preparation Errors:
1.
Failure to mix tube immediately - full or partial clotting of specimen may
occur.
2. Hemolysis - red blood cells broken down and components spilled into serum
(see below).
3. Incomplete filling of the tube, thereby creating a dilution factor excessive for
total specimen volume.
4. Failure to separate plasma from cells within 30-45 minutes of collection.
D. Hemolysis
Grossly or even moderately hemolyzed blood specimens may not be acceptable
for testing. Hemolysis occurs when the red cells rupture and hemoglobin and
other intracellular components spill into the serum. Hemolyzed serum is pink or
red, rather than the normal clear straw color.
Generally, hemolysis is the product of a poor venipuncture. A redraw will often
yield an acceptable, non-hemolyzed specimen.
III.
CRITERIA FOR BLOOD SPECIMEN REJECTION
1. Improperly identified or unidentified specimens.
2. Specimen too old for accurate testing (refer to specific test for such time
requirements).
3. Anticoagulated specimen that is partially or completely clotted.
4. Improper tube type used for specimen collection (i.e. wrong anticoagulant,
serum rather than plasma, etc.).
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5. Patient did not follow specific instructions associated with certain test
procedures. Special instructions may be obtained by calling Altoona Hospital
Department of Laboratory Services at (814) 889-2161.
6. Quantity not sufficient for testing.
One of the most common and expensive errors in specimen collection is the
submission of an insufficient sample for testing. Although Altoona Regional
Health System Laboratory will make every effort to complete testing on the
specimen submitted, we may have to send out a report marked QNS (quantity
not sufficient) and the patient will have to be called back for repeat collection
at additional expense and inconvenience to the patient and to the physician.
To ensure an adequate quantity of specimen:
a. Always check the test section of this manual prior to venipuncture to
determine the specimen type and quantity needed.
b. Always draw whole blood in an amount 2 1/2 times volume of serum
required for a particular test. Example: If 4 ml. of serum is required, draw
at least 10 ml. of blood.
NOTE:
If you are not certain that the quantity of specimen collected is
adequate for a particular test, call Altoona Hospital Department of
Laboratory Services at (814) 889-2161 before releasing the patient.
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