Sodium citrate or sodium oxalate : 14 days
Clotted whole blood should be tested within 14 days.
Additional Material Required for Slide and Tube Tests
Glass slides (50 × 75 mm), test tubes (12 × 75 mm), Pasteur
pipettes, isotonic saline, centrifuge, timer, and mixing
322 Concise Book of Medical Laboratory Technology: Methods and Interpretations Test Procedure
Bring reagent and samples to room temperature before
1. Place one drop of Eryclone anti-A or anti-B or anti-AB
reagent on a clean glass slide.
2. To each reagent drop, add one small drop of whole
3. Mix well with a mixing stick uniformly over an area of
4. Rock the slide gently, back and forth.
5. Observe for agglutination macroscopically at 2
1. Prepare a 2–3% suspension of the red cells to be tested
2. Place one drop of Eryclone anti-A, anti-B, anti-A, B
into correspondingly labeled test tubes.
3. Pipette into each of the test tubes, one drop of the test
red cell suspension and mix well.
4. Centrifuge for 1 minute at 1000 rpm (125 g) or 20
seconds at 3400 rpm (1000 g) or incubate at room
5. Gently resuspend the cell button, observing for
agglutination macroscopically.
Agglutination is a positive test result and indicates the
presence of A and/or B antigen. Do not interpret peripheral
drying or fibrin strands as agglutination. No agglutination
is a negative test results and indicates the absence of A
1. (a) Eryclone® anti-A, anti-B and anti-AB reagent do not
show a reaction with crypt antigens (T, Tn, Tk activated
cells) (b) Eryclone® anti-B is truly negative reacting
with acquired B characteristics.
2. In the tube test procedure, it is recommended that
tubes with negative reactions should be recentrifuged
and results read again after 5 minutes so that weak
3. As undercentrifugation or overcentrifugation could
lead to erroneous results, it is recommended that
each laboratory calibrates its own equipment and
determine the time required for achieving the desired
4. Results of forward grouping obtained by using anti-A,
anti-B, anti-A, B reagent should always be reconfirmed
by performing reverse grouping with known red cells.
5. It is strongly recommended that red cells with known
ABO characteristics should be occasionally run,
preferably on a daily basis so as to control reagent
performance and validate test results.
6. After usage, the reagent should be immediately
recapped and replaced to 2–8°C storage.
(Courtesy: Tulip’s Erybank Range)
Human red blood cells possessing the A antigen can be
broadly subdivided into two main subgroups namely A1
and A2 based on their reaction with A1 lectin. A2 subgroups
comprises of weaker subgroups of A such as A1, A2, A3, A4,
Group A red blood cells which agglutinate with anti-A1
lectin are classified as subgroup A1, whereas red blood cells
which do not agglutinate with anti-A1 lectin are classified as
subgroup A2. It is estimated that about 80% of the group A
population are A1 and the remaining A2 or weaker. Anti-A1
lectin is especially useful in selecting blood for an A2 or A2B
recipient whose blood may contain anti-A1 antibodies.
Erybank® anti-A1 lectin is a ready-to-use purified extract
of Dolichos biflorus seeds that is carefully calibrated to
differentiate most A1 cells from A2 cells. It contains a
phytohemagglutinin, which is virtually specific for A1
antigen on the human red blood cells.
Each batch of reagent undergoes rigorous quality
control at various stages of manufacture for its specificity,
a. Store the reagent at 2–8°C. Do not freeze.
b. The shelf life of the reagent is as per the expiry date
mentioned on the reagent vial label.
Human red blood cells possessing A1 antigen will
agglutinate in the presence of seed extract (lectins)
containing phytohemagglutinin specifically directed
Blood Banking (Immunohematology) 323
Agglutination of red cells with Erybank anti-A1 lectin
is a positive test result and indicates the presence of A1
antigen. No agglutination with Erybank anti-A1 lectin
is a negative test result and indicates the absence of the
A1 antigen. Red blood cells that are positive with anti-A
reagent and negative with A1 lectin are classified as A2.
1. In vitro diagnostic reagent for laboratory and
professional use only. Not for medicinal use.
2. The reagent contains sodium azide 0.1% as preservative. Avoid contact with skin and mucosa. On
disposal flush with large quantities of water.
3. Extreme turbidity may indicate microbial contamination/reagent deterioration. Such reagent should
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