Exam 1

Question 1

Between IgM and IgG which is larger?

Answer 1

IgM due to the pentamer shape

Question 2

Between IgG and IgM which crosses the placenta?

Answer 2

IgG

Question 3

Between IgG and IgM which is the most efficient at complement activation?

Answer 3

IgM due to the pentamer shape

Question 4

Which phase is IgG detected

Answer 4

the antiglobulin test phase (AHG)

Question 5

Which phase is IgM detected

Answer 5

the immediate-spin stage (IS)

Question 6

Define polyclonal

Answer 6

antibodies made from several different clones of B cells that secrete antibodies of different specificities

Question 7

Define monoclonal

Answer 7

antibody made from single clones of B cells that secrete antibodies of the same specificity

Question 8

Function of A1 and B cells

Answer 8

used in reverse typing to detect antibodies in patient’s plasma

Question 9

Function of screening cells

Answer 9

detect unexpected antibodies in the patient’s serum

Question 10

Function of ABO antisera

Answer 10

Test for A or B antigens on red blood cells (forward typing)

Question 11

Function of panel cells

Answer 11

used to identify specific antibodies (more detailed than screening cells)

Question 12

Function of LISS

Answer 12

speeds up antibody binding to cells

Question 13

Function of PEG

Answer 13

Concentrates the antibody to make reactions stronger

Question 14

Function of enzymes papain and ficin

Answer 14

they break down proteins to help antibodies stick better to antigens

Question 15

If Anti-A reacts

Answer 15

blood has A antigen

Question 16

If Anti-B reacts

Answer 16

blood has B antigen

Question 17

If Anti-D reacts

Answer 17

Rh positive

Question 18

No reaction to all

Answer 18

O negative

Question 20

DAT vs IAT

Answer 20

DAT (DIRECT) tests if antibodies or complement are stuck to RBCs inside the body

IAT (INDIRECT) tests for antibodies in serum that react in the lab with RBCs

Question 21

Definition of differential DAT

Answer 21

breaks down whether it’s IgG or complement (C3) causing the positive DAT result

Question 22

Most common positive DAT conditions

Answer 22

Hemolytic disease of the newborn and transfusion reactions

Question 23

Reasons for false-negatives in AHG testing

Answer 23

Didn’t wash cells properly
Forgot to add AHG
Delayed testing
Weak reactions missed
Bad reagents
Wrong red cell concentration

Question 24

Reasons for false-positives in AHG testing

Answer 24

Dirty tubes/glass
Over-centrifuged
Already agglutinated before testing

Question 25

Polyspecific AHG includes

Answer 25

Anti-IgG and Anti-C3D which tells us if IgG or complement is coating RBCs

Question 26

Why is IgG-Sensitized red cells used

Answer 26

They're check cells, if a test is negative, adding these should cause agglutination. If no agglutination, something is wrong

Question 27

Tube grading

Answer 27

4+ = solid chunk 3+ = big clumps 2+ = medium clumps 1+ = small clumps Mixed = some clump, some not 0 = nothing

Question 28

Gel grading

Answer 28

4+ = agglutinate stuck at top 3+ = mostly at top 2+ = throughout tube 1+ = mostly at bottom Mixed = agglutinate on top, free cells at bottom 0 = tight pellet at bottom