5- Diagnosis II

Question 1

Describe the serum virus neutralization test to determine antibody titer

Answer 1

1) Serially dilute serum
2) Add each dilution to separate wells of cultured cells
3) Add equal amounts of virus to each well containing cultured cells and serum dilutions
4) Last dilution that can prevent plaque formation is antibody titer

Question 2

Describe the immunofluorescence antibody test to determine antibody titer

Answer 2

• requires a microscope with fluorescence capability
• used to demonstrate the presence of antibody in serum
• uses an anti- IgG secondary antibody labeled with a fluorescent marier
• can use serial dilutions of patient’s serum over a number of wells to find last well that has fluorescence= ‘titer’