CQ blood cell and anti-serums reagents.pdf

Division of
Blood Transfusion Service
Ministry of Health and Family Welfare

Quality Control In Immunohematology

Teaching Aim
To be able to evaluate and select the proper reagents to ensure
Quality.

Serological tests in blood banks
 ABO grouping and Rh typing
 Weak D (or Du as earlier named) testing
 Antibody detection and identification
 Cross matching
 Antibody titration
 Direct antiglobulin test
 Haemagglutination inhibition test (for secretor status in saliva)

Blood Bank Reagents
 Type of blood bank reagents
• Detect an antigen present or absent on RBC
(donor/patient red cells) eg.- antisera
• Detect antibody present or absent in serum (donor/patient
serum) eg.- reagent red cells
 You need to have a known source of antigen to detect antibody
or known antibody to detect antigen.

ANTIBODIES
Derived from different B
Lymphocytes cell lines
POLYCLONAL MONOCLONAL
Derived from a single B cell
clone
Batch to Batch variation
affecting Ab reactivity &
titre
 Reproducible
 Predictable
 Potentially inexhaustible supply
of Ab with exquisite specificity
Enable the development of
secure immunoassay systems.
NOT Powerful tools for
clinical diagnostic tests

Advantages
 Not contaminated with other proteins
 Consistently reproducible affinity & specificity
 Can be produced indefinitely in unlimited quantities
Disadvantages
 Difficult preparation
 High cost
Monoclonal Antibody

Selection of Antisera
 Antisera must be of high quality with a shelf life of at-least one
year of use and should be received in cold chain
 Should contain a preservative to minimize contamination.
 Should be stored in the refrigerator at 2-8°C
 Should be used according to manufacturer's instructions

Selection of Antisera (contd…)
 Must comply with the standards laid down for potency (titer
and avidity) and specificity
 New reagents should not be introduced into routine work until
internal QC testing have confirmed that they are satisfactory
 Should be clearly labeled with :
• Batch number
• Expiry date
• Storage temperature

Appearance
 Reagent must be clear.
 No turbidity, precipitate, particles on visual inspection
Specificity
 Clear-cut reaction with RBC bearing the corresponding antigen(s)
 Do not contain any other antibody specificity
What specifications need to be considered?

Potency: it is measured by
A] Titer
 It is the highest dilution of the antisera at which the
macroscopic agglutination is seen at strength of 1+
B] Avidity
 Avidity means the overall strength of reaction between
antigen and antibody
 It is measured by the time duration in seconds for the
appearance of macroscopic agglutination
What specifications need to be considered? (contd…)

Specificity
 Label clean three test tubes for each antisera to be used
 Add 2 drops of antisera to be tested
 Put one drop of 2-5% red cell suspension of known ABO group
red cells in respective tubes
 For eg add corresponding red cells suspension in three glass test
tubes for testing the specificity of anti A antisera.
Anti-A
+
A red cells
Anti-A
+
B red cells
Anti-A
+
O red cells

Avidity
 Label a clean glass slide for each antisera to be used
 Put one drop of 10% red cell suspension of respective ABO
group.
 Put 1 drop of respective antisera adjacent to the drop of red cell
suspension
 Mix both the drops using disposable applicator stick
 Start the stop watch simultaneously
 Observe and note the time required for visible agglutination over
the view box

Titer – doubling dilution
 Label 10 test tubes
 Add one volume of saline to all test tubes except the first tube
 Add an equal amount of antiserum to each of the first two tube
 Using a clean pipette mix the contents of the 1 in 2 dilution
several times and transfer one volume into the next tube
 Continue the same process for all the dilutions, using a clean
pipette to mix and transfer each dilution

Titer – doubling dilution (contd…)
 Add 1 drop of the corresponding red cell suspension (5%) into
each test tube. Mix well and keep these test tubes at room
temperature for at least 15min
 Centrifuge all these test tubes at 1000 rpm for 1min.
 Examine test results macroscopically; grade and record the
reactions

Dilution and Titer
 Dilution is expressed as: 1 in 16
which means that the dilution factor is 16
 Titer is simply the inverse of dilution. So, it is the number at
which the end point agglutination (1+) is achieved.
e.g. At titer of 16 is recorded for end point agglutination at a
dilution of 1 in 16.

Dilution and Titer (contd…)
 The first tube is a NEAT on i.e. without any dilution
 The second tube contains one part serum and one part of
normal saline.
 Hence, it becomes 1 in 2 dilution
( It can be written as 1 : 1 and read as 1 is to 1 )

Titer – doubling dilution (contd…)
Normal saline
1 2 3 4 5 6 7 8 9
Anti sera
50μl

Interpretation
 Observe the highest dilution that produces macroscopic
agglutination
 The titer is reciprocal of the dilution level for e.g 32 for 1:32
 If there is agglutination in the tube containing the most diluted
serum, the end point has not been reached, and the additional
dilution should be prepared and tested

Strength of agglutination
4+ One large agglutinate with clear background
3+ Several large agglutinates with clear background
2+ Medium size agglutinates with clear background
1+ Small agglutinates with turbid background
0 No agglutination
Mf Mixture of agglutinated & unagglutinated RBCs
H Haemolysis

Various areas for QC in serology
 Reagents
• Antisera anti-A, anti-B, anti-AB, anti-D, AHG
• Red cells A1, B, O cells
• Medium normal saline
• Potentiator LISS / Albumin / PEG
 Equipment
 Personnel
 Techniques

Anti-A, Anti-B, Anti-A,B (Monoclonal Antibodies)
 Anti-A, Anti-B
• blends of 2-3 MoAbs to optimize the intensity of
agglutination for a slide tests & the potency for detection
of the weaker sub groups e.g. Ax & Bw
 Anti-A,B
• blends of at least 2 MoAbs to optimize both A & B
reactions
• Anti-A+B
• blends of Anti-A & Anti-B MoAbs

Quality Assurance in Blood Grouping
 Use of standardized reagents
 Daily QC of reagents
 Tubes should be clean & dry to avoid false positives
 Serum should be added first followed by red cells
 Hemolysis during antigen antibody reaction is considered as
positive reaction
 Macroscopic readings may require agglutination viewer
 Negative reactions can be confirmed microscopically

Quality Assurance in ABO Grouping
 Ideally, test should be done using test tubes
 Test should be done at room temperature (220C)
 Tubes should be clean and properly labeled
 Both, Cell & Serum grouping should be performed
 Anti- AB may be included for confirmation of group O and weak
variants of A and B
 Serum grouping using pooled red cells
 Pooled cells should be prepared daily and check for specificity
 Serum grouping helps detect irregular antibodies and Bombay
phenotype

TRANSFUSION MEDICINE - TECHNICAL MANUAL
Directorate General of Health Services
Ministry of Health & Family Welfare
Government of India
Second Edition 2003
Sponsored by
WORLD HEALTH ORGANISATION
Liaisons
DRUGS CONTROLLER GENERAL (INDIA)
CENTRAL DRUGS STANDARD CONTROL
ORGANISATION
DGHS CRITERIA

Parameter Quality Requirements Frequency
Appearance No turbidity , precipitate, particles or gel
formation by visual inspection
Each day
Specificity Clear reaction with red cells having
corresponding antigens and no reaction
with negative control
Daily and
each new
lot
Avidity Macroscopic agglutination with 10% red
cells suspension using slide test
Daily and
each new
lot
Reactivity No immune hemolysis , rouleaux
formation or prozone
Each new
lot
Potency Sera should give 3+ reaction in saline tube
test using a 3% red cell suspension at R.T.
Each new
lot
Quality Control of ABO Antisera

Quality control - antisera
Antisera Titer Avidity
Anti-A
A1 cells
A2 cells
A2B cells
>256
>128
> 64
3 -6 Sec
5 – 6 sec
5 – 6 sec
Anti-B
B cells
A2B cells
>256
>128
3 – 4 Sec
5 – 6 sec
Anti – AB
A1 cells
B cells
A2 cells
>256
>256
>128
3 – 4 sec
3 – 4 sec
5 – 6 sec

Worksheet for QC of Anti-A antisera
Parameters Required quality control
criteria (DGHS)
Name of the firm
Date of Manufacture
Date of Expiry
Lot No.
Quantity
Appearance
 Turbidity
 Precipitate
 Particles
No
No
No
Specificity
 A1 cells
 A2 cells
 B cells
 O cells
3 – 4+
3 – 4+
Negative
Negative
Reactivity
 Immune hemolysis
 Rouleaux
 Prozone
No
No
No
Avidity
 A1 cells
 A2 cells
 A2B cells
3 – 4 sec
5 – 6 sec
5 – 6 sec
Potency (titre)
 A1 cells
 A2 cells
 A2B cells
1:256
1:128
1:64
Fulfilling DGHS criteria
Remarks:
Signed by: 1 2 3
Signature of HOD

Lectins
 Lectin is a seed extract that has antibody specificity
 Lectins do not contain antibodies, instead they contain proteins
that react similar to antibodies
 Used to identify certain types of blood group antigens by binding
to the carbohydrate determinant of the antigen, resulting in
agglutination
 Other use of Lectin is to investigate red cell polyagglutination
 Some examples
• Dolichos biflorus (binds A1 antigen)
• Ulex europaeus (binds H antigen)

QC of anti-A1 and anti-H lectins
Reagent Red cells Titer Avidity (s)
Anti-A1
A1 1:16 15-20
A2 neg
O neg
Anti-H
O 1:16 15-20
A1 1:1
A2 1:8
Oh neg

Pooled Red Cells
 Pools of red cells from 3–5 blood donors
• Represent all clinically significant antigens
 Prepared daily
• Identify and record donor unit number
• Confirm the group
• Wash 3 times with saline
• Add equal volume of washed red cells in a tube
 Prepare working solution (5%)
• Add 1 drop of pooled cells to 19 drop of saline
 Check specificity
• Example: B cells should react with anti-B only

QC of reagent red cells - specificity
Known red cells Anti-A Anti-B
A 4+ Neg
B Neg 4+
O Neg Neg
O Rh D neg Neg Neg

Inclusion of O cells & autocontrol is must in reverse
grouping to rule out
 Bombay blood group
 Auto antibodies
 Allo antibodies
 Rouleaux formation

Everyday QC of antisera & reagent red cells
Reagent Red
cells
Anti-A
Lot /batch
Anti-B
Lot / batch
Anti-AB
Lot / batch
Anti-D
Lot / batch
A1
3 donor Unit no
4+ Neg 4+ Not
Applicable
B
3 donor unit no
Neg 4+ 4+ Not
Applicable
O pos
3 donor unit no
Neg Neg Neg 4+
O neg
3 donor unit no
- - - Neg

Quality Assurance in Rh Grouping
 Anti-D in duplicate for confirmation of Rh D negatives
 Use of one IgM and one blend of IgG + IgM preferable
 If Rh D negative, Weak D test to be done in case of donors

Each day
Specificity Clear reaction with O positive red cells and
no reaction with O negative cells
Daily and
each new lot
Avidity Macroscopic agglutination with 40% red
cells suspension using slide test
Daily and
each new lot
Reactivity No immune hemolysis , Rouleaux formation
or prozone
Each new
lot
Potency Sera should give 3+ reaction in saline tube
test using a 3% red cell suspension at R.T.
Each new
lot
Quality Control of anti-D Antisera

Type of
reagent
Type of
red cells
Titer
Immediate
spin
Titer
30 min
incubation
Avidity
time (s) Strength
IgM
monoclonal
O
positive
1:64-1:128 1:64-1:128
(at RT)
5-10 3+
Blend of
IgM+IgG
monoclonal
O
positive
1:32-1:64 1:128-1:256
(at 370C)
10-20 3+
Acceptable Titer & Avidity

Worksheet for QC of anti-D (IgM+IgG) antisera
Parameters Required quality control criteria
(DGHS)
Name of the firm
Date of Manufacture
Date of Expiry
Lot No.
Quantity
Appearance
 Turbidity
 Precipitate
 Particles
No
No
No
Specificity
 O Positive cells
 O Negative cells
3 – 4+
Negative
Reactivity
 Immune hemolysis
 Rouleaux
 Prozone
No
No
No
Avidity
 O Positive cells
(R1 R1)
10 – 20 sec
Potency (titre)
O Positive cells (R1 R1)
 Immedaite spin
 30 to 45 minutes incubation
1:32 – 1:64
1:128 – 1:256

Anti Human Globulin Reagents
 Detects IgG antibodies and Complement protein that have
attached to RBC.
 2 Types
• Polyspecific
• Monospecific

Polyspecific AHG Reagent
 Used in AGT to detect in vivo attachment of IgG and/or
complement on the surface of the red cell or in serum
 Usually available as combination of Anti-IgG and Anti-C3d

Monospecific AHG Reagents
 Used in the investigation of positive DAT to determine the nature
of molecules attached to the red blood cells
 Differential DAT with monospecific AHG can detect IgG or C3 on
the red blood cell surface
 Several formulations exist:
1. Anti IgG
2. Anti-C3d

Quality Control of AHG Antisera
 Each vial of a new batch tested for its specificity and sensitivity
with IgG coated red cells as positive control and non-sensitized
red cells as negative control.
 The potency of anti-IgG of AHG reagents can be estimated by
titration using IgG (anti D) sensitized red cells
 Minimum requirements for quality product of AHG :
Anti IgG 1:64
Anti C3/C4 1:4

Each day
Reactivity
& Specificity
No Prozone phenomenon Each new
lot
No hemolysis or agglutination of unsensitized
red cells
Each new
lot
Agglutination of red cells sensitized with
anti-D sera
Daily
complement binding antibody
Each new
lot
C3b and C3d
Each new
lot
Quality Control Of AHG Antisera

Worksheet for QC of AHG (anti IgG + anti C3d)
Parameters Required quality control
criteria (DGHS)
Name of the firm
Date of Manufacture
Date of Expiry
Lot No.
Quantity
Appearance
 Turbidity
 Precipitate
 Particles
No
No
No
Specificity
Agglutination with
 O Positive unsensitized
cells
 O Positive sensitized cells
No
Yes
Reactivity
 Prozone
No
Potency (titre)
 O+ve anti D (IgG)
sensitized cells
1:64
Remarks:
Signed by: 1 2 3
Signature of HOD

QC of Normal Saline
Parameter Quality
Requirement
Frequency
Appearance No turbidity /
particles
Daily
pH 6.8 to 7.4 New batch
1 ml saline + 1 ml 5% RBC,
centrifuge for 10 min.
Observe for hemolysis
No hemolysis New batch

What are reagent red cell panels?
 Red cell suspensions used in tests employing the principles of
hemagglutination and hemolysis for the detection and
identification of blood group antibodies.
Commercial
 Sources Regular local donors
In-house
Staff members/volunteers

Applications of Reagent Red Cells
 Reverse ABO grouping
 Antibody screening
 Antibody identification
 Antibody titration
 Allogeneic adsorption
 Preparation of Check cells

Learning Outcomes
 You now understand the difference between monoclonal and
polyclonal reagents
 You will know how to evaluate and select a reagent
 You will be able to carry out quality assessment of reagent
available and in use in your laboratory

CQ blood cell and anti-serums reagents.pdf

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