Question

#2 20p. Calculate the number of Influenza virus particles, PFU, in 1 ml of serum of an individual suffering of Influenza infection. You used 0.6mls of 1/4000 serum dilution to inoculate a monolayer of indicator cells on a petri dish. Two days later you enumerated 200 PFU on the tissue culture well

#3 60p. You have in your laboratory three different antisera specific for the Influenza virus:

Antiserum A, was identified previously with a Western blotting assay to bind specifically to a viral surface protein employed by the H1N1 virus to attach to human epethilial cells.

Antisera B is binding to a viral nucleoprotein of the same H1N1 virus while

Antisera C is binding specifically to a viral surface protein employed by the H5N1 virus to attach to human epethilial cells.

You performed a virus neutralization test similar to the one performed in laboratory #7. You may assume that you used the same volumes and serum dilution as in question #2

-Outline briefly the protocol (basic experimental groups) that would allow you to characterize the putative neutralizing properties of the three antisera

-Predict the number of Influenza PFUs caused by H1N1 virus employing antisera A, B and C under optimal conditions of virus and antibody concentrations

Answer 1

2) According to the question, 0.6 mL of 1/4000 dilution serum was plated & 200 PFU were counted.

So, in 0.6 mL of serum (without dilution) number of PFU = 200 x 4000 = 800,000

So, in 1 mL of serum number of influenza virus particle = (800,000/0.6) PFU = 1,333,333 PFU