Antiglobulin testing

Question 1

Detects the RED CELLS COATED IN VIVO with immunoglobulins or complement.

Answer 1

Direct Antiglobulin Testing (DAT)

Question 2

Washed red cells from a patient or a blood donor are TESTED DIRECTLY with ANTI-HUMAN GLOBULIN (AHG) reagents.

Answer 2

Direct Antiglobulin Test (DAT)

Question 3

It indicates that the PATIENT HAS ANTIBODY ATTACHED TO THE RED CELLS that occurred in vivo.

Answer 3

DAT positive

Question 4

[3] DAT is used to detect:

Answer 4

1. HDFN
2. AIHA
3. Sensitization of the red cells due to drugs and medications

Question 5

It is applied during the investigation of SUSPECTED TRANSFUSION REACTIONS and hemolysis due to ABO incompatible platelet transfusions or mismatched organ transplants.

Answer 5

Direct Antiglobulin Testing (DAT)

Question 6

Spin the tubes for 1 minute at?

Answer 6

3000 rpm

Question 7

To the DRY RED BLOOD CELL BUTTON on each tube, deliver ____ of AHG Coombs reagent.

Answer 7

2 drops

Question 8

The CONTROL must be ___ to have a VALID RESULT.

Answer 8

negative

Question 9

What does the Direct Antiglobulin Test (DAT) detect?

Answer 9

Red cells coated IN VIVO with immunoglobulins or complement

Question 10

Reagent used to test WASHED RED CELLS in the DAT.

Answer 10

Anti - Human Globulin (AHG)

Question 11

HEMOLYSIS due to what type of INCOMPATIBLE PLATELET TRANSFUSION may require a DAT?

Answer 11

ABO incompatible

Question 12

What is the preferred blood collection tube for DAT?

Answer 12

Lavender top (EDTA)

Question 13

What is the required concentration for the red cell suspension in this procedure?

Answer 13

2% - 5%

Question 14

In the sample preparation for the POSITIVE CONTROL (T1Pos), what reagent is added to the 1 ml of RBC suspension?

Answer 14

Anti - D

Question 15

How long should the T1Pos tube stand after adding anti-D during sample preparation?

Answer 15

At least 5 minutes

Question 16

How many drops of RBC suspension are delivered into the testing tubes (T1Pos and T2Neg)?

Answer 16

1 drop

Question 17

How many times must the tubes be washed before adding AHG?

Answer 17

3X

Question 18

What is the centrifuge speed and time for each wash cycle?

Answer 18

3000 rpm for 1 minute

Question 19

How many drops of AHG Coombs reagent are added to the dry cell button

Answer 19

2 drops

Question 20

What is the centrifugation setting AFTER the AHG incubation?

Answer 20

3000 rpm for 15 secs

Question 21

What is added to all negative DAT results to VALIDATE them?

Answer 21

Check cells

Question 22

If results are less than 2+ after adding check cells, what must be done?

Answer 22

Repeat the washing procedure

Question 23

For a DAT result to be considered valid, the control must be:

Answer 23

Negative

Question 24

What happens to the test result if the NEGATIVE CONTROL (T2Neg) is found to be POSITIVE?

Answer 24

Invalidated

Question 25

According to the interpretation table, a result of Polyspecific 3+, Anti-IgG 3+, and C3 0 is interpreted as:

Answer 25

Positive (IgG)

Question 26

What size test tubes are used in this protocol?

Answer 26

75x12mm

Question 27

What should be the appearance of the red blood cell button AFTER DECANTING during the wash?

Answer 27

Dry (supernatant removed)