Diagnosis 2 (5)

Question 1

What laboratory techniques do you use for antibody detection?

Answer 1

enzyme-linked immunosorbent assay (ELISA)
immunofluorescent antibody
serum virus neutralization (SN)
AGID (ouchterlongy)

Question 2

____ gives immediate results, + or -

Answer 2

ELISA

Question 3

What is the principle of serology tests?

Answer 3

based on 4 fold rise in antibody level between acute and convalescent sera

Question 4

What is the problem with serology tests?

Answer 4

requires 2 samples to be collected
- 1st often collected too late (i.e. already contains antibody)
often difficult and cost prohibitive to collect sound sample

Question 5

What does ELISA look for?

Answer 5

antibodies
serum sample: to be tested containing antibody to the virus
sample already has a virus so we can see if we have antibodies

Question 6

What does a serum virus neutralization test do?

Answer 6

determine antibody titer

Question 7

What do you do in a serum virus neutralization test?

Answer 7

serially dilute serum
add each dilution to separate wells of cultured cells
add equal amounts of virus to each well containing cultured cells and serum dilutions
last dilution that can prevent plaque formation is antibody titer

Question 8

The [first/last] dilution that can prevent plaque formation is the antibody titer

Answer 8

last

Question 9

What does the immunofluorescence antibody test do and use?

Answer 9

used to demonstrate the presence of antibody in serum
uses an anti-IgG secondary antibody. labeled with a fluorescent marker

Question 10

T/F: You can use serial dilutions of patient’s serum over a number of well to find last well that has fluorescence in immunofluorescence antibody test

Answer 10

FALSE - cannot

Question 11

What happens in a hemagglutination inhibition of antibody?

Answer 11

mix serial dilutions of patient’s serum with known amount of virus particles
antibodies in patient’s serum inhibit the virus’s ability to agglutinate rbcs
read titer of antibodies where it stops inhibiting agglutination

Question 12

What does AGID (Agar Gel Immunodiffision, Ouchterlony) detect?

Answer 12

antibody produced in response to infection

Question 13

What are the uses of AGID (Agar Gel Immunodiffision, Ouchterlony)?

Answer 13

under-developed countries
some diseases is still a test of choice
used in research development of new diagnostic tests, such as ELISA