IgM versus IgG

Question 1

What type of antibody structure is IgM?

Answer 1

Pentamer

Question 2

What type of antibody structure is IgG?

Answer 2

Monomer

Question 3

How many antigen binding sites does IgG have?

Answer 3

2

Question 4

How many binding sites does IgM have?

Answer 4

10

Question 5

Is IgM naturally occurring an immune/adaptive antibody?

Answer 5

Naturally occurring

Question 6

Is IgG naturally occurring or an immune/adaptive antibody?

Answer 6

immune/adaptive

Question 7

What is the optimum reactivity temperature of IgM?

Answer 7

25C or lower

Question 8

What is the optimum reactivity temperature of IgG?

Answer 8

37C

Question 9

Does IgG react in saline?

Answer 9

No

Question 10

Does IgM react in saline?

Answer 10

Yes

Question 11

What is the strength of complement fixation (binding) of IgM?

Answer 11

Strong

Question 12

What is the strength of complement fixation (binding) of IgG?

Answer 12

Moderate

Question 13

What antibody crosses the placenta?

Answer 13

IgG

Question 14

Can IgG cause transfusion reactions?

Answer 14

Yes

Question 15

Can IgM antibodies cause transfusion reactions?

Answer 15

Usually only the ABO antibodies

Question 16

Does IgM antibodies cause hemolytic disease of the newborn?

Answer 16

No

Question 17

What antibody causes hemolytic disease of the newborn?

Answer 17

IgG

Question 18

What antibody causes delayed hemolytic transfusion rxns?

Answer 18

IgG

Question 19

What antibody is destroyed by sulfhydryl compounds? (DDT, 2-ME)

Answer 19

IgG.

NOT IgM.