Quality Control

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Quality Control
12.1 INTRODUCTION
Stringent quality control in blood banking is essential because the product (blood and component) issued
is meant for human consumption.
Quality control is a means that assures supply of a quality product (blood and component as per
quality requirement) processed through a comprehensive programme designed tv function within the
defined specification and parameters of a particular task/tasks to obtain a perfect product satisfying the
needs (stated or implied) of all concerned (dispenser, user, consumer), Implicit in it is the notion of
proper documentation, proficiency survillance, review ofthe standard operative procedure which includes
donor selection. QC of reagents as per laid down specification. QC of technical operation and equipment.
QC of component separation, transfusion practices. This has to be reviewed from time to time and
adjusted to ensure transfusion of safe, pure and potent blood and products, judicious administration of
whichis apt to be efficacious.
Documentation forms the sheet anchor for safe transfusion practice rather, it may be reflection of
correct laboratory performance in a blood bank. The requisition form that includes all details of patient
with statistical number is required for identification ofthe accompanying blood sample. A proper checking
and cross checking is essential. A record of all tests, controls and observations in respect of the blood
sample and in respect of compatible unit issued to a particular patient. Preservation of recipient sample
and donor units are the routine blood banking procedure that ensures supply ofquality blood or component
as per demand prescribed by the user depending on the necessity of consumer. Periodic review of records
will indicate any corrective action deemed necessary to ensure quality control.
Proficiency survillance is another aspect which very often overlooked. Personnel quality control
can be ensured through periodic proficiency testing programme and corrective measures taken to make
up the deficiency through CME (continued education programme) and training etc. A personnel should
not always be posted to one section continuously for a long period and be rotated in different sections of
the department so that he has knowledge of other sections of the department. A standard operative
manual with uptodate addition and revisions must be maintained in each laboratory. This standard operative
manual differs from laboratory to laboratory and acts as a guideline for the technologist.
Quality control can be achieved through quality survillance of the quality requirement of the product
(blood and component) through internal quality control and external assessment.
357

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Blood Banking and Transfusion
Quality requirement is the standard set by national body (Drug Controller) in respect of a product.
Quality survillance is done again by an authorised body competent for the purpose.
Internal quality control is done within the blood bank by continuously monitoring the different
activity of blood bank that includes investigative, diagnostic, therapeutic, banking and manufacturing.
This monitoring is done separately by one senior technical officer who recommends the necessary
corrective measure in respect of reagents, equipments, procedures or any other deficiency observed by
him in regard to functional flow, design and management that concerns the quality control.
External assessment is done by an outside agency either by comparing all the datas with that of
reference laboratory or by cross checking the datas of one laboratory with other laboratory for the set of
samples and procedures etc.
12.2 QUALITY CONTROL OF REAGENTS
Antisera bovine albumin, enzyme, reagent red cell
All quality control test is done within the premises of blood bank in a quality control laboratory by a
person designated for the purpose. He/She is usually a senior technical officer who has the authority to
take necessary corrective measure.
Antisera
Anti-A, anti-B, anti-AB and anti-Rh (D), all these antisera must comply with the standard laid down for
specificity and avidity to make them acceptable in the laboratory.
Labels
All these antiseras should be properly labelled, label should contain date of manufacture, date of expiry,
batch No., lot No., storage instruction, production licence No., information about preservatives, standard
colour used according to acceptable norms, name of antisera and that they are free from HIV, HbsAg
and HeV.
Inspection
The contents to be used within the date of expiry and the reagents, with turbidity and discolouration is
suggestive of contamination and not to be used.
Daily check of reagents in morning or before use is essential or any new vial-ofany new consignment
should also be checked before use. They are all checked for specificity and avidity and should comply
with as given in the Table 12.1. Reagents to betested according to instructions supplied by manufacturer.
Rh (0) antisera be additionally checked, if possible with R, r (CcDee) and IT (Ccdee) and rare cells
likeRor (celzce), rr (Ccdce) and r"r (CcdEe) to confirm the specificity particularly in polyclonal reagent.
The minimum criteria for checking is specificity, avidity, date ofexpiry and firmness to agglutination
checked with respective cells.
All the antisera should be crystal clear on visual inspection i.e., it should not contain/show any
particles, precipitate, gel. It must show a clear cut reaction with specific cells. Avidity not more than
'<
described in Table 12.1, 12.2 and 12.3. Perform test twice and duplicate results should agree within 3
seconds.

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359
For specificity, red cell suspension of 290 from at least t\VO donors are to be tested for each antisera
as described in Table 12.1, 12.2 and 12.3, in addition. all antisera are also tested with 'a'cells.
Storage
24 months at 2°C to 8°C monoclonal reagent commonly used source is non-human murine hybridoma
and thus, it is IgM murine monoclonal antibody. With fresh serum, it may show haemolysis which could
be due to presence of complement.
Frequency of test daily before you start the laboratory work and each time with fresh new lotlbatch.
Rh (D) reagents are used to detect the Rh (D) positivity and Rh (D) negativity. Rh (D) is most immunogenic
and has a higher frequency distribution amongst the all five varieties of Rh. Further the 'd' is hypothetical
and is reported to be non-existent. In view of all these Rh 'D' has assumed more clinical significance and
as such while detecting Rh in laboratory especially in blood for transfusion purpose, the transfuionist
prefer to restrict to Rh 'D' only unless the associated condition warrants a detailed and expanded
investigation. Therefore, while declaring Rh positive, the transfusionist declares the Rh status of the
sample with reference to the existence of 'D' in that particular sample of blood. If 'D' is found to be
existing by serological test, the sample is declared Rh +ve and is denoted by a superscript on right hand
side of major blood group, e.g. B+similar by where'D' is not detected is declared and Rh negative and
denoted B" and like wise. An Rh negative case has to be further evaluated for presence of Du by AHG
because the anti-'D' sera available are not capable to detect Du. Most of the Rh antibody belongs to
subclass of IgG but few of them also belongs to IgM. A proper mixture/blend of both the subclasses will
be in fitness of requirement to detect the different epitopes of human red cell antigen D (Rho). A feature
that will add versatility to the reagent. The different parameters of anti-D (Rho) is given below.
While doing test run both positive and negative control and in negative cases the auto control is also
applied. Reagents must be free of contamination and turbidity, specific for anti-'D' and 'show clearcut
reaction, no immunohaemolysis or rouleaux formation.
Table 12.1. Avidity and specificity antisera
Antisera
2% red cell
Titre at the
Avidity with
Firmness of *
suspension
end of 60 min.
50% cell
agglutination observed
in saline
incubation at Rtf
suspension
at two min.
Anti-A
Al
1 : 256
10sec.
+++
A2
1 : 128
15 sees to 18 sees
++ to +++
A2B
1 : 64
15 sees to 18 sees
++
x
Anti-B
B
1 : 256
10 sees
+++
AlB
I : 256
10 sees
+++
Anti-AB
Al
1 : 256
10 sees
+++
B
1. : 256
10 sees
+++
A2
1 : 128
15 sees to 18 sees
++ to +++
* Firmness of agglutination depends on cell type and varies accordingly.
x
Anti-B (Monoclonal) should be truly negative with acquired B.

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Blood Banking and Transfusion
Table 12.2. Avidity anti-D sera
Type of
20% saline
Reactivity
5% saline
Titre by tube
Remarks
antisera
suspension
suspension
and spin
slide at 40°C
in 1 min
]5 min
spin (tube)
at 37°C
IgG
15 to 20 sees
+++ to ++++ at
+++
128to 256
Du not detected
(Avidity)
end of two min.
Blend of IgG
15 to 20 sees
+++to ++++ at
+++
128 to 256
90% cases Du
and IgM
end of two min.
detected by tube
monoclonals
and 60% by slide
IgG polyclonal
30 to 60 sees
+++
+++
1 : 32
Table 12.1. Avidity and specificity antisera
Antisera
5% cell suspension
Titre spin for
Avidity
Firmness to agglutinaton
in saline
one min
Anti-A
A] cells
1 : 16
15 to 20 sec.
+++
(Dolichos
A2 cells
Negative
-
-
Bit1orus)
a cells
Negative
-
-
Anti-H
Al cells
1 : 1
15 to 20 sees
+ to ++
(Eulex
A2 cells
1 : 8
-do-
++
Europaeus)
'0' cells
1 : 16
-do-
+++
'Oh' phenotype
Negative
--
-
Lectins
Two types of lectin reagents are used commonly anti-A 1 (Dolichos) and anti-H (Ulex) for detection of
Al and Bombay/para-Bombay phenotype or secretor status of individual respectively.
For secretor status determination by anti-H, incubation at RT prior to centrifugation is required and
incubation is for 15 to 20 minutes depending on type of antisera used.
Bovine serum elbumir.
It is available commercially as 22% and 30% albumin used as agglutination potentiator or as stabiliser
that is used in other reagents strength varies between 1 to 7%.
It is mainly used in albumin displacement technique for Rh (0) typing and 22% albumin is quiet
sufficient for this purpose.
It is said that the potentiating effect of albumin is due to :
(i) Increase in dielectric. constant.
(ii) Presence of albumin polymers (85% monomer and 15% polymer). 22% solution is specially
used in blood grouping and to .be stored at 4°C. Care should be taken not to freeze during
storage. Sodium azide is used as preservative. Globulin part is removed by cold alcohol
fractionation.

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Quality Control
361
BSA should be free of non-specific agglutinin and should not react with saline suspension of A~ B
and 0 cells.
It should give positive reaction with Rh (D) positive cells coated with incomplete anti-Rh (D), run
positive and negative control, IgG anti-D tested with CDElcde red cells give a titre of 32-64.
Protein concentration between 20 to 30% and beyond this red cell may not react.
.Saline solution
Commonly used in blood banking practice is 0.9% saline solution also known as isotonic or physiological
or normal saline solution on visual inspection, it should appear crystal clear with no turbidity and
particulates visible.
Na(:;/ content
0.85% of Sodium Chloride is isotonic for human RBC and as such the content should not exceed 0.9
gm%.
pH : Between 6.0 to 8.0.
It should not cause any haemolysis of red cell when 0.1 1111 of 5% red cell suspension is treated with
0.1 rnl of normal saline incubated at RT for ten minutes and then centrifuged. A standard solution does
not cause haemolysis.
Fleagent red ceJls
These are prepared by pooling of three to five units of fresh blood of respective group viz. AI' A2, B and
o cells. They should be tested daily after preparation and to be kept in blood bank refrigerator, if not in
use.
These pooled cells should be tested for specificity.
They should be free of haemolysis.
Neutiel Af-3 reagents
They are obtained from group AB donors. Tests are done at .37°C, 4°C and RT by saline, albumin,
enzyme and ICT with 0, AI' A2 and B red cells to detect any antibody and also tested to detect other
antibodies particularly anti-Bg and anti-Wr.
Enzynie reagents
They are bromelin, trypsin, ficin and papain. Most commonly used is papain and cystein in combination
and is used to detect Rh (D).
A quality papain cystein mixture has a pH of 6.2. No reaction or haemolysis with neutral AB serum
and firm agglutination, even with weak IgG after incubation at 37°C for thirty minutes.
Each vial, new batch should be tested separately for testing specificity and sensitivity, IgG coated red
cells to be used for the test.

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Blood Banking and Transfusion
AHG is a polyspecific reagent and consists of anti-C3/C4, anti-IgG, anti-IgM and anti-IgA activity.
Each test is run with a positive and negative control. Non-specific reaction ruled out by testing with
A, B and 0 cells. Test cells should not be sensitised.
Validity of AHG tests are to be confirmed by positive reactive reaction with IgG coated cells.
Any reagent on visual inspection must be crystal clear and reagent must not show prozone or
haemolysis on testing.
Agglutination checked daily with IgO (preferably anti-D) coated red cells.
Agglutination checked for each new batch :
(a) IgG (preferably anti-D) coated red cells.
(b) For complement activity, checked with red cells coated with C3b, C3d and \C4• It is also tested
with sensitised red cells coated with complement binding antibody (anti-Lea)'
Minimum requirements are given below:
Anti-IgG
1 : 64
Anti-IgM
1 : 4
Anti-C3/C4
1 : 8
Anti-IgA
Preferable
Commercially available product with higher values are found viz. :
Anti-IgG
1 : 512
Anti-C3b
1 : 32
Anti-Cal
1 : 16
Different kits
For testing my, HbsAg, HCV and VDRL are to be tested daily as per instruction with run of positive
and negative control.
Each new batch to be tested for false positivity and false negativity, standardised before being
introduced. Buffered solution commonly used are to be checked daily before use. The pH of solution
should range between 6 to 8 or as per requirement. On visual inspections, it must appear clear with no
turbidity and particulate, no haemolysis,
Haemoglobinometry
It is done by different methods in different centre :
(a) CuS04 method
(b) Sahlis method
(c) Cyanemethaemoglobin method
(a) The copper sulphate method through a crude estimation of Haemoglobin by specific gravity,
it is adopted in blood banking for its simple technique, can be done quickly in any laboratory
or in the field
Quality control
(i) Stock SOlution f170 gm crystalline CuS04, 5H20 is dissolved in 1000 ml of d.w.).

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(ii) Working solution (52 ml of solution is added to 49 ml of distilled water).
Specific gravity of working solution 1.053 (considered equivalent to 12.5 gmldl haemoglobin).
For .QC test random blood samples, and specific gravity variation allowed is ± .0003 of required
value. A 30 ml solution is used for doing 25 tests or solution should be changed daily.
Blood collected by finger prick, collected and allowed to drop gently from higher of approx. 1 em
above the. surface of CuSO4 solution. Squeezing of finger for collection is to be avoided, use clean
pipette and flush, flush out thoroughly.
(b) Sahil's method (acid haematin method, chemical method to estimate iron content)
Quality control
(i) Correct pipetting up to 20 Cu mm.
(ii) No squeezing or milking during collection of blood..
(iii) Fill calibrated tube upto mark 20 with 0.1 N HCI.
(iv) Fresh solution of O.IN HCI is to be used.
(v) Clean arid dry pipette and haemoglobin tube to be used.
(vi) Reading to be taken by keeping haemoglobinometer at level of eye in good day light.
(vii) Bottom of meniscus to be recorded in grams per cent.
(c) Cynamethaemoglobln or haemcglobinocyanide (HlcN) method
The International Committee for Standardisation in Haematology recommended this method in 1966,
the method was modified later which was recommended by same Committee in 1978.
The principle is based on the following reaction of blood. The blood when mixed with a diluent
containing potassium ferricyanide and KeN. The former oxidises haemoglobin to methemoglobin and
the later provides cyanide and forms haemoglobinocyanide. The absorbance of this solution at 540 nm is
compared with a standard solution of HicN.
QC of diluent
pH 7.0 to 7.4 clear pale yellow solution and gives a zero reading at 540 nm in photometer.
QC of procedure
Exactly 20 ml of test sample is added to 50 ml of diluent (1 : 251). Incubated at RT for three minutes
only.
Absorbance is measured against reagent blank in photoelectric colorimeter at 540 nm, use an
appropriate filter.
Test sample should not be retained untested for long diluent stock solution is preserved at RT in.
dark container and fresh solution is prepared every month when not in use standard kept in dark and
discard at end of day.
12,,3 BLOOD AND BLOOD COMPONENT
Whole human blood should be tested negative for HeV, HbsAg, mv,VDRL, MP for transfusion purpose
in India.

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Blood Banking and Transfusion
Specific gravity
1.05 to ].06.
Volume
It varies from centre to centre and acceptable collection is 10% ± of volume recommended in the pack
The pack could be of 300 ml/350 mV450 ml and the anticoagulant used is either CPO or CPOA @ "I,
mlllOO ml of blood. Weight of 350 ml is approximately 470 gms volume can be calculated as follows
Weight of the whole unit (bag + blood) in gms - Weight of bag with anti-coagulant
Specific gravity of particular content
PCV
It should be 30 to 40% in whole blood. No contamination (bacterial or particulate) no haemolysis or clo
should be observed on visual inspection.
Red cell concentrate
The red cell is residue that remains in the blood bag after plasma is expressed out.
Quality requirement demands that it should be free of contamination (bacterial, particulate), passer
all the mandatory tests, haemotocrit 70%, specific gravity 1.09, volume 280 ml ± 10% (when processer
from 450 ml blood bag).
Platelet reach plasma (PRP)
Platelet count as per quality requirement demands that 75% of PRP samples tested gives a count of 6 >
IOlOlbag of PRP processed from 450 ml of whole blood.
Platelet concentrate
Volume 50 to 60 ml pH 6, platelet count (from 350 ml of whole blood) is around 4.3 x lOla/per unit anc
75% of units checked should give this count. The platelet concentrate must be free of contaminatior
(bacterial and particulate) though the platelets can be preserved for seven days but time recomrnendec
for usage is limited to 5 days only and as such PC unit that has crossed 5 days limit is not to be considerec
quality product.
Leucocyte poor red cell
Quality requirement recommended varies as per manufacturing procedure. Ifprepared by centrifugation:
the parameter is 70% of WBC removed and 70% RBC of the original quantity is retained, If prepared by
microaggregate filter, WBC removed is less than 70% and red cells retained is 90 to 95%. Units to be
tested for these parameters once in every four months.
Cryoprecipitate
Assayed on at least 4 bags per month, if there is mass production of CPPT or it can bedone proportionate
to the rate of production. For Factor VIII, assay can be done with factor deficient plasma collected from

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365
haemophiliacs. Degree correction ofcr can be determined by in vitro addition of test plasma to substrate
plasma and thus amount of F VIII can be calculated by comparing the obtained value with a known
value. Different parameters are as follows:
Volume
15ml to 20 ml
F VIII C
80 to 120 units
Fibrinogen
150to 250 gms
VWF
40 to 70% of original
F XIII
20 to 30% of original
F II, V and IX
Small amount
Fibronectin
55 mg
Fresh trozen ptesme
It should be separated from whole blood within 6 hours of collection.
Volume
200 ml to 250 ml (variable depends on original unit of blood)
Stable coagulation factors
200 units
Factor VIII
0.6 I.U.lml
Fibrinogen
250 to 400 mgm
Gran,ulocytes
Again depends on the manufacturing procedure.
By refrigerated centrifuge
Processed 450 nil blood
White cells : 1 x 109
(Granulocytes are about
half 0.5 to 0.6 x 109)
Volume - 200 to 250 ml of plasma
By leucapheresis
(Cell separator)
Volume - 200 to 400 ml of plasma
granulocyte 0.5 to 1 x 1010
other WBC - 0.1"to 0.7 x 1010
Platelet 2 to 10 X 1010
RBC 10 to 50 ml
HES must not exceed 12% ofplasma volume
12.4 TECHNIQUE, OFFICE PROCEDURE (RECORD, MEDICAL AUDIT)
-In blood bank, a smooth operation of technique is a basic necessity that determines the quality and
standard of performance. Each operation is subject to some degree of inaccuracy or possible fault which
is bound to reflect on the reliability of the product, i.e., quality. Direct link of quality and standard of
performance envisages the need for quality control oftechnique and technician to minimise the procedurall
technical error in functional flow (technique or otherwise) or to identify the errors so that proper remedial
measure may be taken to eradicate them.
Technical errors may be due to omission, inadequate skill, improper monitoring etc., so built in
control system to check the error is required. This may be as follows:
(a) Reverse grouping while doing A, B, o grouping.
(b) To run positive control, negative control and autocontrol in any serological tests or wherever
recommended.

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Blood Banking and Transfusion
(c) Two different anti-D while doing Rh grouping.
(d) Rh (D) negative cases to be followed up by Du test.
(e) Maintenance of proper incubation at recommended temperature and time.
(f) Employ the recommended rpm while centrifuging and not over centrifuge or under centrifuge.
(g) Validity test for AHG by using IgG coated cells for confirming the result.
(h) To confirm doubtful agglutination under microscope.
(i) Accurate pipetting, weighing.
(j) Proper and adequate washing.
(k) Too weak or too strong suspension of cells.
(1) Carefully observe for haemolysis.
(m) Proper cross matching in saline, albumin and AHG at R.T. and warm phase, cold phase, if
necessary. Major and minor cross matching has its own significance.
(n) Screening for irregular antibody in incompatible blood before issue.
(0) Preserve the reagent cells, antisera samples and other reagents at appropriate/recommended
temperature.
(p) While using kits HbsAg, HeV, HIV, VDRL the instructions are to be followed properly and use
of controls is a must.
(q) Not to use the unlabelled or inadequately labelled samples, reagents and seras.
(r) Maintain a dust free atmosphere and room temperature inside routine working laboratory,
adequate,
\.'~
:)dtion and lights is also necessary.
(s) Saline (N)t
\
id distilled water are to be used wherever indicated and not haphazardly.
These are only fev. out of numerous omissions that commonly occurs in a blood bank laboratory by
a blood bank technician and to ensure a good quality product, quality control of technique or monitoring
is necessary.
Office procedure includes proper maintenance of records, medical audit by Hospital Transfusion
Committee. All these plays significant role in quality control of blood and blood products.
Record
It has a definite role in blood bank system/work procedure. Clerical mistakes frequently leads to mishap
"that may result in fatality. So whatever observation has been done is to be properly interpreted and
recorded, if required, it may be confirmed by another person before recording. All records, directions,
instructions are to be initialled. Records are to be reviewed frequently by supervisory staff. I Blood or
sample are to be properly labelled as per instruction while issuing or receiving this rule is to be strictly
adhered. Requisition forms and transfusion reaction form etc. are to be filled up properly initialled and
stamped (name, designation etc.). Records for last ten years are to be preserved.
Medical audit
Though the duty of blood bank is apparently over with issue of blood, but it is not completed till transfusion
is conducted safely. This includes the review of practices and policy in relation to blood transfusion ;
(a) Ensure proper blood has been transfused to the identified person.

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(b) Transfusion set supplied contains filter, plastic spike etc. and they are gamma irradiated and
sterile.
(c) No plasma or component are issued frozen, it should be thawed and than issued.
A transfusion committee should be set up for the purpose of doing medical audit. Transfusion
committee does the following function :
(a) Monitor the source of supply for purity and potency of the product issued.
(b) Infection control programme related to blood bank and services.
(c) Differentaspectsof transfusion: Specialisedtransfusion(cardiovascular, paedeatricandneonatal,
marrow transfusion, intrauterine and autologus transfusion etc.).
(d) Judge the efficacy of transfusion and recommend for judicious transfusion.
(e) Introduce medical auditing and/or new medical and technical procedures.
(f) Continued medical education to upgrade the blood banking services through up to date
knowledge.
(g) Follow up transfusion reaction cases.
(h) Study work load in blood bank and rearrange the infrastructure accordingly to meet up the
increasing needs.
.(i) Tum around time to be watched and curtail unnecessary delay.
(j) Monitor the working of error detection system and recommend the remedial steps.
(k) Monthly review of the problems viz., logistics, finance, personnel, technical and resolve them.
(1) Incentive for good work by personnels/technician.
12.5 EQUIPMENT
Equipments are the integral part of any blood banking and transfusion services. Starting from collection,
preservation, processing and component separation, the equipments forms an essential part. So all the
equipments should be as per specifications and the quality control of equipments are required to processl
produce quality product. So maintenance of equipments through periodical services and fault repair is
needed. Periodical review andcalibrationto provideaccuracyof performancefor uninterruptedfunctional
flow forms a part in 9uality control. Each equipment must have a logbook so that any machine beyond
economical repair can be condemned and better equipment/machine can be purchased :
(a) Blood bank refrigerator: Dailyrecordof temperatureatleast 12hourly. Idealrange of temperature
is 2°e to 6°C any variation must be notified and properly attended, check the alarm system and
inner cabinet temperature by precision thermometer.
(b) Walk-in-cooler: They are used in places where daily stock is more than ~OO to 300 units. Same
criteria as above holds true for walk-in-cooler also.
(c) Deep freezer: Criteria same as above. Long life and durability can be ensured through periodic
defrosting and clearing as in caseB. Bank refrigerator.
(d) Refrigerated centrifuge: Periodical checkup and calibration by qualified service engineer is
essential who recommends for any change, if required. Weeklycheck with tachometer and stop
watch.

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Blood Banking and Transfusion
(e) Still distillation plant: Periodic descabing is essential check for purity and pH (6.3 to 8.3) of the
product, any change, chemical, bacteriological and physical parameters is indicative of problems
that may be in the plant. This needs proper attention.
(f) pH meter: Control solution pH 4 to 7, 7 to 10 periodical check up yearly by service engineer.
(g) Lab centrifuge (ordinary) : Periodical check up for accuracy of speed and time by tachometer
and stopwatch.
(h) Incubator; water bath, hot air oven: Check temperature daily by thermometer and periodical
check up of insulation electrical connection.
(i) Spectrophotometer: Check calibration daily, periodical check up and maintenance half yearly
by qualified service engineer.
(j) Microscope : Keep it with cover when not in use, lubrication at periodic interval of 3 to 4
months of hinges, mechanical joints, sliding devices. Objectives, lenses are cleaned regularly
with moistened lens paper.
(k) Automatic cell washer: Parameter checked is volume of supply, frequency daily. Monthly check
of tubing and its function whether proper cell button forms or not. Compare same sample by
duplicate titration, one washed by cell washer, the other washed manually, ~cores
should not
vary widely.
(1) Weighing scale for collecting blood: Parameter volume ± 10 ml, frequency daily. Checked by
comparing with known weight or volume.
(m) Ordinary refrigerator: Record upper and lower temperature daily 2/3 times.
(n) Cell separators : Checking regularly at periodic interval by qualified service engineer. Any
defect in operation is reflected through cornputerised control system.
(0) Freezers working at ultra-low temperature: Contents are kept frozen at a temperature of (-)
150°C (-) 196°C in an atmosphere of liquid Nitrogen vapour (Fig. 12.1).
OC of contents
The products (mainly rare RBCs) after separation, 250 ml of
red cell suspension treated with 250 ml solution containing
38%w/v glycerol, 2.9% sorbitol, 0.63% sodium chloride
mixed with vigorous shaking.
Container
I. RBC container: Polyolefin plastic bags.
2. Container for bags: Cylindrical shaped aluminium
container or a standard aerosol container kept in
upright position ina bath of liquid Nitrogen.
Freezing
Parameter RBCs reach O°Cby 8 minutes, followed by rapid
freezing approximately @ (-)20°C/sec.
Fig. 12.1. Ultralow freezer (-150°C to -
195°C) operator wearing cryogloves to
bring out frozen bags from liquid nitrogen
atmosphere.

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Quality Control
369
Deglycerilisation
Thawing is done first at 37°C water bath for 10 minutes, Deglyceroliscd by washing once in solution
containing 17.5% mannitol and 0.8% sodium chloride followed by two more washing in saline
successively. Deglycerolised red cell volume and haematocrit should not be less than standard unit of
red cell suspension and the red cells are in a suspension of electrolytes virtually devoid of anticoagulant,
leucocyte plasma and,platelet.
Blood. ~dlTlinistTation
set
These are the set through which blood is administered or transfused, It is supplied separately alongwith
each unit of bloodlblood bag.
Memoryless tubing made up of biocompatible material composed of vinyl' chloride monomer with
diethylhydoroxypthalate with fixed needle (18-19 g for adult and 23 g for infant and children) and
internally fitted filters. Supplied in a sterile pack (gamma ray irradiated) with date of expiry mentioned.
Filter
Different types of filters are fitted for wide ranging transfusates and are used according to needs :
1. 170 Jl pore size up of nylon mesh:
(a) Nylon mesh with small dead space (commonly used), whole blood.
(b) Lexan plastic nylon mesh : For all type of tranfusate.
2. 40'fl pore size, microaggregate filter made of pleated polyester mesh or 27Jlpolyester urethane
foam for all types of blood components mainly used in cardiovascular bypass surgery, while
transfusing blood more than 5 days old to filter the aggregate of platelet and leucocyte.
3. 2,5 m pore size made up of cotton and nylon filter to specifically filter the leucocytes only.
Books and [ournels recommended for
'~urth'9r
rC21d:rag
'Books
1. A HandbookofMedical Labo.ratory Technology, Talib, V.H., 1988 edition, Spons.ored by WHO.
.
2. BloodTransfusion in Clinical Medicine, Mollison, P.L, seventhedition, 1983,BlackwellScientificPublication.
3..Clinical Diagnosis and Management by LaboratoryMethod of Todd, Sanford and Davidshon; edited by
John Bernard, second Indian edition, 1989, AITBS.
.
4. Standardsfor BloodBan/a; and Transfusion Services, Bhatia, Chayya, Gupta, Jolly, Koticha, Saran;Verma,
1987,DGHS, MOH and F~
Nirman Bhawan, New Delhi.
.
5. Transfusion Medicine Technical Manual, Saran and Makroo, 1991, Sponsored by WHO and DGHS.
Journals
I. Bharucha; Zarin, S., QualityAssurance in Blood Banks Immunohaematology Bulletin, Vol. 2,3,. No.3, .pp.'J
to 10, May-June, 1992.
2. Bharucha Zarin, S., Recent Developmentin Transfusion MedicineImmunohaematology Bulltein, Vol. 20,
No.1, pp. 2 to 9, Jan.-Feb. 1983.
~.
Transfusion Bulletin, Vol.
~, No.1, pp. 2 to 10, April-June1993.