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Sample Collection and Preparation

No special preparation of the patient is required prior

to sample collection by approved techniques. Samples

should be stored at 2-8°C, if not tested immediately. Do

not use hemolyzed samples. Anticoagulated blood using

various anticoagulants should be tested within the below

mentioned time period:

EDTA or Heparin : 2 days

Sodium citrate or sodium oxalate : 14 days

ACD or CPD : 28 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, mixing sticks.

Test Procedure

Bring all reagent and samples to room temperature before

testing.

Slide Test

1. Prepare a 10% suspension of the red blood cells to be

tested in isotonic saline.

2. Place one drop of Erybank anti-A1 lectin on a clean

glass slide.

3. Pipette two drops of the cell suspension on the slide.

4. Mix well with a mixing stick uniformly over an area of

approximately 2.5 cm2

.

5. Rock the slide gently, back and forth.

6. Observe for agglutination macroscopically at one

minute.

Tube Test

1. Prepare a 5% suspension of the red cells to be tested

in isotonic saline.

2. Place one drop of Erybank anti-A1 lectin into a labeled

test tube.

3. Pipette into the test tube, one drop of the test red cell

suspension.

4. Centrifuge for 1 minute at 1000 rpm (125 g) or 20

seconds at 3400 rpm (1000 g).

5. Gently resuspend the cell button, observing for

agglutination macroscopically.

Interpretation of Results

Slide and Tube Tests

Agglutination is a positive test result and indicates the

presence of A1 antigen. Do not interpret peripheral drying

or fibrin strands as agglutination. No agglutination is a

negative test result and indicates the absence of A1 antigen.

Remarks

1. A1 antigen is not fully expressed on the red blood

cells of newborns below one year of age, hence, false

negative results may occur.

2. It is strongly recommended that known A1 and A2

cells should be occasionally run, preferably on a daily

basis to control reagent performance and validate test

results.

3. A1 A2 (Aint) cells may agglutinate moderately with

Erybank®. Anti-A1 lectin. These should be tested further

with Anti-H lectin to confirm Aint cells.

4. As undercentrifugation or overcentrifugation can lead

to erroneous results, it is recommended that each

laboratory calibrate its own equipment and determine

the time required for achieving the desired result.

ANTI-H LECTIN

Ulex Europaeus Lectin for

Slide and Tube Tests

(Courtesy: Tulip’s Erybank Range)

Summary

The H antigen is a basic blood group antigen present in

human beings. There is considerable variation in the H

antigen content in different individuals of the same ABO

group, but the general pattern indicates their strength as

O>A2>A2B>B>A1>A1B. Water-soluble H substance can also

be demonstrated in saliva or body fluids of individuals

324 Concise Book of Medical Laboratory Technology: Methods and Interpretations who are secretors. Human red blood cells that do not

agglutinate with Anti-H lectin are classified as Bombay

phenotype (Oh). The Bombay phenotype is more common

in India than other parts of the world and the estimated

gene frequency of Oh phenotype in Bombay is 0.0066%.

Reagent

Erybank Anti-H lectin is a ready-to-use purified extract of

Ulex europaeus seeds. It contains a phytohemagglutinin

which is virtually specific for the H antigen on human red

blood cells. Erybank Anti-H lectin is used for recognition

of the H antigen on human red blood cells. It is useful,

especially for assessing the H secretor status of group

‘O’ individuals and also in differential grouping of Aint

subgroup along with anti-A lectin.

Reagent Storage and Stability

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.

Principle

Human red blood cells possessing the H antigen will

agglutinate in the presence of seed extract (lectins)

containing phytohemagglutinin specifically directed

towards it. Water-soluble H substance present in saliva

neutralizes anti-H lectin. Agglutination of red blood cells/

neutralization of anti-H lectin by saliva is a positive test

result and indicates the presence of H substance on/in the

red cell/saliva respectively. No agglutination/neutralization

of anti-H lectin is a negative test result and indicates the

absence of H substance on/in the red cell/saliva respectively.

Note

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

be discarded.

Sample Collection and Preparation

For Recognition of H Antigen on Human Red Blood Cells

No special preparation of the patient is required prior

to sample collection by approved techniques. Samples

should be stored at 2–8°C, if not tested immediately. Do

not use hemolyzed samples. Anticoagulated blood using

various anticoagulants should be tested within the below

mentioned time period:

EDTA or heparin : 2 days

Sodium citrate or sodium oxalate : 14 days

ACD or CPD : 28 days

Clotted whole blood should be tested within 14 days.

For Assessing Secretor Status in Human Saliva

a. Collect about 2 mL of fresh saliva in a glass tube and

incubate in a boiling water bath for 10 minutes.

b. Centrifuge at 3400 rpm (1000 g) for 10 minutes.

c. Use the clear supernatant immediately for the study

or freeze immediately if to be tested later.

Additional Material Required for Slide and Tube Tests

Glass slides (50 × 75 mm), test tubes (10 × 75 mm), Pasteur

pipettes, isotonic saline, centrifuge, timer, mixing sticks,

red blood cells positive for H antigen, red blood cells

negative for H antigen, saliva positive for H antigen, Saliva

negative for H antigen.

Procedure

Bring all reagent and samples to room temperature before

testing.

Slide Test

1. Place one drop of Erybank anti-H lectin on a clean

glass slide.

2. Add one drop of whole blood to be tested on the slide

and mix well with a mixing stick uniformly over an area

of approximately 2.5 cm2

.

3. Rock the slide gently, back and forth.

4. Observe for agglutination macroscopically at 2 minutes.

Tube Test

1. Prepare a 5% suspension of the red cells to be tested

in isotonic saline.

2. Place one drop of Erybank anti-H lectin into a test tube.

3. Pipette into the test tube, 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).

5. Gently resuspend the cell button, observing for

agglutination macroscopically.

Tube Test (Secretor Status)

1. Place two drops of anti-H lectin into two clean glass

tubes.

2. Pipette two drops of saliva into the tubes and mix well.

3. Incubate at room temperature for 10 minutes.

4. Add one drop of negative and positive cell suspensions

into the tubes, mix well and incubate at room temperature for 5 minutes.

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