Remarks

1. Erroneous test results can occur from microbial or

chemical contamination of buffered saline. The final

reagent so obtained should be a clear solution.

2. Isotonic buffered saline obtained from Osmosol

should not cause hemolysis of red blood cells, gel

formation with serum under test. Any observable

change in serum or cellular elements, the reagent must

be discarded.

3. Occasionally, it is recommended that the pH of the

isotonic buffered saline obtained from Osmosol

should be checked before using for serological

applications. The pH should be in the range 6.9–7.2.

Any change in pH value out of the specified range, the

reagent should be discarded.

4. The isotonic buffered saline obtained from Osmosol

should be strictly stored in scrupulously clean,

sterile beakers/glass wares and not in plastic

containers.

5. The 20X concentrated Osmosol vial may show fine

particulate appearance if stored at 2–8°C. This can be

overcome by gently warming the concentrated solution

to 25°C, before dilution.

Media for Collection and Preservation of

Reagent Red Cells

1. Modified Alsever’s solution:

 Dextrose—2.05 g

 Sodium citrate—0.8 g

 Citric acid—0.05 g

 Sodium chloride—0.45 g

 Distilled water—100 mL

 (Expected pH = 6.1).

2. Serum lactose solution:

 Lactose—10 g

 Dextrose—1.53 g

 Sodium citrate—1.38 g

 Citric acid—0.5 g

 Distilled water—100 mL.

This 100 mL solution is mixed with 100 mL of serum

from a person of group AB (serum must be free of irregular

and cold agglutinins).

Precautions

Antisera must be refrigerated when not in use. Reagents

and blood specimens for hemagglutination test must be

handled aseptically since bacterial contamination may

cause both, falsely negative and falsely positive results.

Positive and negative controls must be run daily with all

antisera.

RED CELL PRESERVING SOLUTION FOR

SEROLOGICAL APPLICATIONS

(Erywell from Tulip)

Summary

In blood group serology, known red cell panels are of

immense value in confirming the results of forward grouping,

antibody screening and detection of rare phenotypes. A red

cell preserving solution is utilized to preserve the red cells of

interest. Erywell red cell preservation solution is formulated

specifically for enhanced preservation of red cells carrying

clinically important phenotype or genotype, which are

required for routine immunohematological practice.

Reagent

Laboratory reagent. Ready-to-use solution.

Erywell red cell preserving solution is a standardized

Alsever’s solution for maintaining red cell integrity and

survival.

Principle

Red blood cell shrinkage and loss of antigenic properties

are observed on storage. To preserve the red cells for a

longer time and ensure enhanced usage life for serological

procedures, the Erywell solution supplies the necessary

nutrients, salts and preservatives for maintaining red cell

integrity and antigenic properties useful during serological

procedures.

Storage and Stability

Store the reagent at 2–8°C.

Blood Banking (Immunohematology) 329

Stability of unopened vial: 12 months from the date of

manufacturing.

Additional Material Required

1. Freshly collected red blood cells in EDTA dipotassium

salt (1.5 mg/mL of whole blood).

2. Test tubes 12 × 100 mm, scrupulously clean and dry.

3. 10 mL pipettes, scrupulously clean and dry.

4. 500 µL micropipette and micropipette tips.

5. Freshly prepared normal saline (0.9% NaCl).

6. Table centrifuge.

7. Sterile 10 mL vials.

Procedure

Quick Method for Whole Blood Preservation

1. Collect 5 mL whole blood in EDTA dipotassium salt

(1.5 mg/mL of whole blood). Add equal volume of

Erywell solution to it. Gently mix the solution.

2. Before using the red cells prepared by the quick

method, it is recommended to wash the red cells

three times with normal saline before use for testing

purpose.

Preparation of 2/3/5% Stabilized Red Blood Cell

Suspension in Erywell Solution

1. Collect 2 mL of freshly drawn venous blood in a

clean and dry test tube containing 3 mg of EDTA dipotassium salt.

2. Add 5 mL of normal saline solution and mix well.

3. Centrifuge the tube at 3000 rpm for 2–3 minutes to

form a red cell button.

4. Discard the supernatant.

5. Resuspend the red cell button in normal saline

solution.

6. Centrifuge the tube at 3000 rpm for 2–3 minutes.

7. Repeat the washing of the red cells (steps 4 and 5) one

more time in normal saline.

8. After the centrifugation, remove the supernatant

without disturbing the red cell button.

9. Now resuspend the red cell button in 5 mL of Erywell

solution.