Immunodiagnostics - Bowden (Completed)

Question 1

What is required for Serological Assay Diagnostics to be possible? 3

Answer 1

Either the Ab or Ag must be available in a pure detectable form

Question 2

Define Sensitivity? What does poor sensitivity result in? 4

Answer 2

Ability to detect small quantities of Ab or Ag

Poor sensitivities –> False negatives

Question 3

What can be said if sensitivity of an assay is very high? 4

Answer 3

You can rule out disease

Question 4

Define specificity? What does poor specificity result in? 4

Answer 4

Ability to distinguish immunogen from other Ags

Poor specificity –> false positives

Question 5

What can be said if the specificity of an assay is very high? 4

Answer 5

You can rule in disease

Question 6

Differentiate Direct vs Indirect Assay Methods? 6

Answer 6

Direct –> detects Ag

Indirect –> detects Ab (antiserum)

Question 7

What is a DFA test? 7

Answer 7

Direct Fluorescent Antibody test

Fluorescent-labeled Ab used to detect Ag in tissue

Question 8

What is an IFA test? 8

Answer 8

Indirect Fluorescent Antibody test

Test Ag introduced into test pt serum

Pts Abs bind Ag

IgG flourescent Ab binds pt Ab and concentration of pt ab against Ag can be determined

Question 9

What is the point at which precipitation occurs in a precipitation reaction? 9

Answer 9

Equivalence point (equivalence zone)

Question 10

What is Ouchterlony? 10

Answer 10

Used to determine if two Ags contain overlapping epitopes

Question 11

What is an Agglutination reaction? 11

Answer 11

Similar to precipitin reactions, but the target Ag is part of a whole cell

IgM used

Question 12

What is a common example of a test that uses an agglutination reaction? 12

Answer 12

Blood typing

Question 13

What is the COOMBS test? 13

Answer 13

Using anti-human Igs, RBCs bound with Anti-Rh abs are agglutinated

Question 14

What is a direct Coombs test? 13

Answer 14

Detects anti-Rh Abs found on fetal RBCs

Question 15

What is indirect Coombs test? 13

Answer 15

Detects anti-Rh abs in mothers serum

Question 16

What is the most popular Ab labeling method? 14

Answer 16

Indirect labeling

Question 17

What is an ELISA test? 15

Answer 17

Fluorescent Abs are introduced into a solution containing Ags attached to a plate wall

If Abs bind reaction undergoes and color change is shown

If Abs doens’t bind it is washed away and no color change is shown

Question 18

What is the goal of western blot? 17

Answer 18

To identify protein, separates by weight

Question 19

What is flow cytometry? 18

Answer 19

Abs bind cell surface markers, laser beam counts