Evaluation of the gel system for ABO grouping and D typing.
BACKGROUND
The gel agglutination assay has been approved by the Food and Drug Administration as an alternative to the tube assay for the detection of red cell antibodies. It has also been approved recently by the Food and Drug Administration for ABO blood grouping and D typing.


METHODS
Tube and gel agglutination assays were compared for ABO grouping and D typing of 100 donor and 100 patient specimens. ABO grouping of 14 specimens of known ABO groups and D typing of 10 specimens with weak D were also compared. When antigen typing or isohemagglutinin results differed, gel testing was repeated by the use of modified incubation times, reagent or specimen volumes, and red cell concentrations.


RESULTS
ABO grouping and D typing in all patient and donor specimens concurred. B isohemagglutinins were not detected in seven group A specimens. Six of seven discrepancies were resolved when gel tests were incubated at room temperature with increased serum or plasma volume. Weak D was detected in all 10 specimens tested by both assays. When weak A and/or B were tested with monoclonal antibody reagents, the correct phenotypes were identified in 9 specimens by gel assay and in 10 by tube assay. Using human antisera, 6 specimens were correctly phenotyped by gel assay and 7 by tube assay.


CONCLUSIONS
The gel assay performed as well as the tube assay in detection of A, B, and D, but the tube assay was slightly better at detecting B isohemagglutinins. The gel assay can be used in place of the tube assay for ABO blood grouping and D typing.
Langston
M M
MM
Department of Transfusion Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892-1184, USA.
Procter
J L
JL
Cipolone
K M
KM
Stroncek
D F
DF
D000017:ABO Blood-Group System / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000918:Antibody Specificity; D000925:Anticoagulants; D001788:Blood Grouping and Crossmatching / Q000379:methods*; D002614:Chelating Agents; D002648:Child; D002675:Child, Preschool; D004492:Edetic Acid; D005069:Evaluation Studies as Topic; D005260:Female; D005782:Gels; D006386:Hemagglutination Tests / Q000379:methods*; D006388:Hemagglutinins / Q000097:blood* / Q000276:immunology; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood / Q000276:immunology; D012204:Rh-Hr Blood-Group System / Q000276:immunology*; D018029:Rho(D) Immune Globulin; D012680:Sensitivity and Specificity; D013696:Temperature
D000017:ABO Blood-Group System; D000925:Anticoagulants; D002614:Chelating Agents; D005782:Gels; D006388:Hemagglutinins; D007518:Isoantibodies; C061961:RHO(D) antibody; D012204:Rh-Hr Blood-Group System; D018029:Rho(D) Immune Globulin; C026410:Rho(D) antigen; D004492:Edetic Acid