2.3 DS: Infection and immunity

Question 1

What does ELISA stand for?

Answer 1

Enzyme linked immunosornebent Assay

Question 2

ELISA can be used to detect either:

Answer 2

– ANTIGEN: infectious organism
– ANTIBODY: immune response to infection

Question 3

ELISA: If testing early in the course of infection:

Answer 3

– Test for organism (ANTIGEN) at site of infection
– Antibody production will still be in the LAG phase

Question 4

ELISA: If testing > 5d post-exposure

Answer 4

– Test for antibody in serum (LOG phase)
– Re-test 2-3 weeks later (PLATEAU phase)

Question 5

Sandwich ELISA method used for

Answer 5

Detection of antigen

Question 6

ELISA method for detection of

Answer 6

Antibody In serum

Question 7

Haemolytic bacteria

Answer 7

• produce a toxin that damages cells

Question 8

What is Hemolytic bacteria tested on?

Answer 8

We can test for this by culture on sheep blood agar
- hawmolysis occurs in the petri dsh

Question 9

Antibody titre

Answer 9

• Titration of serum to become more and more dilute
• The greatest dilution that still gives a positive result in the test

Question 10

Bacteria just need

Answer 10

food and a warm place to grow – Nutrient Agar at 37 degrees Celsius

Question 11

What do viruses need in order to replicate?

Answer 11

Cells- Need to culture cells in the lab that the virus is able to infect (NB species specificity and tissue tropism of the virus)