This PowerPoint presentation will provide the steps involved in
the ABO/Rh test tube procedure ABO/Rh Tube Test Procedure
Slide 2
ABO Forward Typing This test is used to detect the presence or
absence of A and/or B antigens on an individual's red blood cells.
An individual's ABO group is determined by testing the red blood
cells with reagent anti-A and anti-B sera. Agglutination of the
individual's red cells by the appropriate antisera signifies the
presence of the antigen on the red cells No agglutination with the
antisera signifies its absence.
Slide 3
ABO Antigens by Blood Group ABO GroupAntigens present on the
red cells Group AA antigen Group BB antigen Group OThere are no ABO
antigens present on the red cells Group ABBoth A and B
antigens
Slide 4
ABO Reverse Typing This test is used to detect ABO antibodies
in an individual's serum, and is used to confirm the ABO
Individuals will produce potent, naturally occurring antibodies
directed against the ABO antigens they lack. The outcome of the
serum typing (Reverse Typing) is compared with the outcome of the
cell typing (Forward Typing) to ensure the accurate ABO
determination. A final interpretation of the blood group is made
based upon the test tube reactions.
Slide 5
ABO Antibodies by Blood Group ABO Blood GroupAntibodies in the
serum/plasma Group AB antibody present Group BA antibody present
Group OBoth A and B antibodies present Group ABNeither A or B
antibodies present
Slide 6
Rh (D) Typing This test is used to detect the presence or
absence of D (Rh) antigens on an individual's red blood cells. - A
person can be either D (Rh) Pos or D (Rh) Neg depending on the
presence or absence of the D (Rh) antigen - Control must be run in
parallel with Rh grouping tests performed on patients samples, to
avoid incorrect designation of Rh Neg, patient as Rh Positive.
Slide 7
ABO/Rh Tube Testing of a patient specimen ABO Grouping
Determination of the patients correct ABO group is the most
critical pre-transfusion serologic test. It is essential that the
ABO/Rh tube testing procedure be performed accurately and according
to the standard operating procedure
Slide 8
Steps of the ABO/Rh Tube Test Locate/obtain all of the
necessary laboratory equipment Obtain suitable patient specimen for
testing Label test tubes and set up test tube rack Dispense
appropriate volumes of reagents/patient specimen Mix
reagents/patient specimen Grade test tube agglutination reactions
Interpret ABO/Rh
Slide 9
Laboratory Equipment Required Specimen centrifuge ABO/Rh
reagents Test tubes-12x75 mm; 10x75 mm Test tube rack Test tube
serofuge Disposable plastic pipettes Sharps container for disposal
of test tubes
Slide 10
Patient Specimen Requirements Specimen collected in EDTA tube
or a clotted tube No hemolysis present Adequate specimen volume
Appropriately labelled with patients full name, date of birth and
hospital unique number
Slide 11
Label Test Tubes and Rack Set-up Test tubes must be labelled
with the last initial and first initial of the patient you are
testing and the reagent you are using For patient Adam Sandler the
test tubes would be labelled as follows: Test Tube
labelReagentGrouping SA-AAnti-A reagentForward grouping SA-BAnti-B
reagent SA-DAnti-D(Rh) reagent SA-DCAnti-D(Rh) control SA-RAA1
cellsReverse grouping SA-RBB cells SA-3%NonePatients 3% cell
suspension
Slide 12
Test Tube Rack Set-Up Each laboratory may have a slightly
different test tube rack set-up For this learning module we will
set up the test tube rack as follows: SA-DC SA-3% SA-D SA-B SA-RB
SA-A SA-RA **Please note: Rack set-up is slightly different than
the set-up in the following video. Most laboratories do not use the
anti-AB reagent and therefore we will not use this reagent in the
ABO/Rh testing procedure.**
Slide 13
Dispensing Reagents/Patient Specimen Specific reagent/patient
specimen volumes need to be added to each test tube Avoid
cross-contamination of reagents or specimens. Follow standard
operating procedure for the volumes required
Slide 14
Mixing Reagents/Patient Specimen Gently mix reagents/patient
specimen in the test tubes Test tube rack can be gently agitated to
mix all test tubes at once Mixing of reagents/patient specimen
ensures adequate antigen/antibody uptake to promote optimal
agglutination
Slide 15
Serofuging Test Tubes Centrifuge test tubes in the serofuge for
the time and RPM stated in the standard operating procedure. Add a
balance tube if required.
Slide 16
Dislodging Cell Button Gently resuspend each cell button
individually and examine for agglutination after serofuging Grasp
the tube lightly at the top, and hold vertically so that the cell
button is facing toward you when viewed in the mirror. VERY GENTLY
shake the tube (shake from the wrist) to dislodge the cell button.
Continuously observe the cells as they come off the cell button.
When the cell button is about one-half broken up, gently tip the
tube horizontally and observe for agglutination.
Slide 17
Additional Notes for Dislodging Cell Button Over shaking can
break up fragile agglutinates, resulting in a false negative
reaction. Failure to completely resuspend the cell button may
result in a mixed-field reaction being missed.
Slide 18
Grading Test Tube Reactions Macroscopic 4+ One solid aggregate
or clump of cells. 3+ Several large aggregates, clear background.
2+ Small to medium sized aggregates, clear background. 1+ Small
aggregates, turbid reddish background. +W Tiny aggregates, turbid
reddish background. MF Mixed Field Any degree of agglutination in a
sea of unagglutinated cells. Hem - Hemolysis is interpreted as a
positive reaction and may be graded as complete or partial. Both
hemolysis and agglutination may be recorded on the same tube.
Negative - no agglutination, smooth reddish background.
Slide 19
Grading Reaction Chart
Slide 20
ABO Interpretation Chart Forward Type ResultsReverse Type
ResultsBlood Group Interpretation Anti-AAnti-BAnti-D(Rh)Anti-D
control A1 CellsB cells +0+00+A POS +0000+A NEG 0++0+0B POS 0+00+0B
NEG 00+0++O POS 0000++O NEG +++000AB POS ++0000AB NEG Note- Do NOT
use + as your interpretation of your agglutination reaction
results. In the following chart + indicates a positive reaction for
agglutination, record your GRADED reactions according to the
grading reaction chart in previous slide.
Slide 21
Please watch the two videos on the ABO/Rh tube testing
technique located in this section. These videos will show you the
steps involved in the ABO/Rh tube test and the techniques required
to accurately perform the testing procedure.
