F07652_101.indd.ps, page 1-2 @ normalize

Summary and Principle
Erythrocytes sensitized with human serum globulins are used as the positive controls in anti-
globulin testing. Erythrocytes sensitized with human IgG should be used with anti-human globu-
lins containing anti-lgG. The binding of anti-lgG in an anti-human globulin to IgG molecules
attached to red cells results in agglutination.
Agglutination of the IgG-sensitized erythrocytes indicates that the anti-human globulin has been added and that its anti-lgG component is active.
Reagent
Coombs Control Cells: group 0 human erythrocytes sensitized with human IgG, provided as a
3±1% suspension in a buffered isotonic medium with neomycin and chloramphenicol as pre-
servatives. Store at 2–8°C.
Do not freeze.
Caution: All blood products should be treated as potentially infectious. Source material
from which this product was derived was found negative when tested in accordance
with current FDA required tests. No known test methods can offer assurance that prod-
ucts derived from human blood will not transmit infectious agents.
The pipette of the vial contains natural rubber latex which may cause allergic reactions.
Ready to use. Do not wash Coombs Control Cells before use. Indication of deterioration:
notable hemolysis and/or turbidity which may be caused by microbial contamination or improper
handling.
Procedure
Reagent Provided
Coombs Control Cells (070205)
Materials Required but Not Provided
1. Anti-human globulin(s)
a. Anti-lgG, -C3d; polyspecifi c
b. Anti-lgG (heavy chains)
2. Centrifuge calibrated for 1000 rcf or 150 rcf (Immufuge® III or DAC III)
Procedure Outline
1. Gently resuspend Coombs Control Cells by repeated inversion of the vial.
2. After examining antiglobulin tests for agglutination, add 1 drop of Coombs Control Cells to
each negative or questionable reaction.
*rcf = 0.00001118 x rotating radius (cm) x rpm2 3. Shake tubes gently to mix reagents and centrifuge for 20 seconds at approximately 1000 rcf* or 1 minute at approximately 150 rcf*.
4. Gently resuspend cells and examine immediately for macroscopic agglutination.
Record Interpretation: Positive - Cells agglutinated 1+ or greater.
Negative or questionable - Cells not agglutinated or cells agglutinated less than 1+.
Results
Agglutination of the Coombs Control Cells indicates that anti-human globulin was added and
that its anti-lgG component was active. Therefore, if performed properly, the original antiglobu-
lin test is valid. Very weak agglutination of the Coombs Control Cells may be due to an insuf-
fi ciently reactive anti-human globulin or inadequate washing of test cells. The original antiglobu-
lin test may be in valid and should be repeated.
No agglutination of the Coombs Control Cells usually indicates that the test cells were inad-equately washed, that anti-human globulin was omitted from the test or that the anti-lgG in the serum was accidentally neutralized. The original antiglobulin test is, therefore, invalid and should be repeated.
Limitation of Procedure
Anti-human globulin lacking antibodies to human IgG will not react with Coombs Control
Cells.
False negative results may occur if
1. Coombs Control Cells are stored improperly and lose reactivity.
2. Cells are improperly centrifuged.
3. Resuspension technique is too vigorous to preserve agglutination.
False positive results may occur if1. Coombs Control Cells or anti-human globulins have microbial contamination.
2. Tests are improperly centrifuged.
Specifi c Performance Characteristics
Each lot of Coombs Control Cells is carefully sensitized and standardized to provide a positive
agglutination control for anti-human globulins containing anti-IgG when used as outlined in
the procedure described. Suffi cient testing is performed on each lot of material to assure its
reactivity throughout the dating period.
Bibliography
1. Stratton, F.; Renton. P.H. Practical blood grouping, Springfi eld: Charles C. Thomas; 1958:
2. Technical manual of the American Association of Blood Banks. 10th Edition: 1990: 477.
Warranty
This product is warranted to perform as described in its labeling and in the product literature,
and Medion Diagnostics AG disclaims any implied warranty of mer chan ta bi lity or fi tness for any
other purpose, and in no event shall Medion Diagnostics AG be liable for any consequential
damages arising out of the aforesaid express warranty.
Medion Diagnostics AG
Medion Diagnostics
Bonnstrasse 9, CH-3186 Düdingen/Switzerland Olympus America Inc.
International Corporation
Copyright 2006, Medion Diagnostics AG.

Source: http://www.mediondiagnostics.us/pdfs/Coombs%20Control%20Cells%20USA.pdf