Section VII: Serology

Question 0

What is immunodiagnosis

Answer 0

detection of antibodies can help provide definitive diagnosis

Question 1

What is serology

Answer 1

refers to the use of serum antibodies to detect and measure antigens or conversely the use of antigens to detect serum antibodies

Question 2

What is Titer

Answer 2

amount of antibody is the titer

• as infection progresses more antibodies are formed and the amound of antibody in the blood increases
• small but steady amounts of antibody could result from infection at a previous time giving important information regarding persons current immunity
• a rise in titer is characteristic of active infection

Question 3

What is serotype

Answer 3

a strain that has a characteristic antigenic structure that differs from other strains
-serotype determination is critical for tracking transmission and emergence of infections

Question 4

What is ELISA

Answer 4

Enzyme-Linked ImmunoSorbent Assay

-uses two antibodies, one of which is specific to the antigen and the other of which is coupled to an enzyme

Question 5

What is agglutination

Answer 5

the interaction between antibody and antigen results in cross linking and lattice formation

Question 6

What is precipitation

Answer 6

the interaction between antibody and a soluble antigen in aqueous solution forms a lattice that develops into a visible precipitate

Question 7

What is immunodiffusion

Answer 7

immune precipitates also form in agar. As antibody and antigen diffuse toward one another a visible line will form

Question 8

What is complement fixation

Answer 8

older test not used much today

• indicator system is red blood cells from sheep
• the presence of of hemolysins and complement the RBCs will lyse

Question 9

What is capsular swelling

Answer 9

quellung reaction

• swelling of the capsule surrounding a microorganism after reaction with an antibody
• typically used for strep

Question 10

What are neutralization tests

Answer 10

• specific antibodies present will neutralize effect of toxin
• not used much today

Question 11

What is immunofluorescence

Answer 11

-fluorescent dyes can be attached to known specific antibodies which are then used to detect the presence of an antigen in serum

Question 12

What is the schick test

Answer 12

intracutaneous skin test enables to distinguish between individuals who are susceptible and those who are resistant to diptheria toxin

Question 13

What is the tuberculin skin test

Answer 13

• not an antibody mediated test
• this is a cell mediated response, specifically
• people who have been exposed to TB will develop immune response causing slight swelling at injection site