BLOOD BANK METHODS (Grading of Agglutination Reactions)

Question 1

Tube method: One solid agglutinate, clear supernatant

Gel method: Solid band of agglutinated RBCs at the top of the gel column, no RBCs are visible at the bottom

GRADE:

Answer 1

4+ (100%)

Question 2

Tube method: Medium-sized agglutinates, clear background

Gel method: RBC agglutinates that are dispersed throughout the gel column, few agglutinates at the bottom

GRADE:

Answer 2

2+ (50%)

Question 3

Tube method: Several large agglutinates, clear supernatant

Gel method: Predominant of agglutinated RBCs near the top/upper half of gel column, few agglutinates below

GRADE:

Answer 3

3+ (75%)

Question 4

Tube method: Small agglutinates, turbid background

Gel method: RBC agglutinates that are predominantly in the lower half of the gel column, some RBCs at the bottom

GRADE:

Answer 4

1+ (25%)

Question 5

Tube method: No agglutination

Gel method: RBCS form a well-delineated pellet at the bottom of the microtube. The gel above the RBC pellet is clear

GRADE:

Answer 5

0 (0%)

Question 6

Tube method: Presence of minor population of agglutinated cells superimposed on a negative background

Gel method: Presence of a layer of agglutinated RBCs at the top of the gel accompanied by a pellet of unagglutinated cells at the bottom of the microtube

GRADE:

Answer 6

Mixed-field (Mf)

Question 7

Encountered in weak ABO subgroup and in patients who had recent blood transfusion procedure:

Answer 7

Mixed-field

Question 8

Other grading observed on tube method:

H

Answer 8

Hemolysis

Question 9

Other grading observed on tube method:

+ or W

Answer 9

Few small aggregates with many unagglutinated cells

Question 10

Other grading observed on tube method:

+^m

Answer 10

Aggregates visible only under microscope

Question 11

Other grading observed on tube method:

R

Answer 11

Rouleaux formation

• stack of coins appearance of red cells
• encountered in cases of multiple myeloma