ANTIGLOBULIN TEST

What does Coomb’s test detects?

1. Incomplete Ab or non-agglutinating Abs

2. Detection of IgG which does not react with saline or high protein media

Indicate whether the ff. statement is DAT or IAT

1. Detects in-vivo sensitization

2. Specimen is RBC

3. Red cell phenotyping

4. Investigation of transfusion reaction

5. Detecting weak D antigen

6. Employed during crossmatching

7. Diagnosis of HDN

8. Detection of red cell sensitization reactions using cephalothin

9. A positive result means presence of circulating antibodies in the patient serum causing sensitization to the red cell

10. A positive result means red cells are sensitized

1. DAT

2. DAT

3. IAT

4. IAT

5. IAT

6. IAT

7. DAT

8. DAT

9. IAT

10. DAT

What is the advantageous ratio of serum to cells on sensitization phase of IAT?

133:1 (4 drops of serum + 1 drop 3% RBCs)

This reaction medium allows antibody-coated cells to come closer contact with each other so that aggregation occurs

Albumin or 22% Bovine Albumin

This reaction medium enhances Ab uptake

Low Ionic Strength Saline (LISS)

This reaction medium is a water soluble linear polymer and used to increase Ab uptake

Polyethylene glycol (PEG)

It produces polyclonal antibodies which recognize different epitopes and uses lab animals

Classic method

Produces monoclonal Ab derived from one clone of plasma cell that recognize a single epitope

Hybridoma Technology

Contains both anti-IgG and anti-C3d

Polyspecific AHG

Contains either anti-IgG or anti-c3d

Monospecific AHG

Indicate whether it could cause false-positive or false-negative

1. Clotted sample refrigerated

2. Autoagglutinable cells

3. Dirty glassware

4. Centrifugation of test with PEG prior to washing

5. Inadequate incubation

6. Under centrifugation

7. Low pH of saline

8. AHG reagent not added

9. Bacterial contamination of cells or saline used in washing

10. Saline contaminated by heavy metals or colloidal silica

1. False-positive

2. False-positive

3. False-positive

4. False-positive

5. False-negative

6. False-negative

7. False-negative

8. False-negative

9. False-positive

10. False-positive