How is IFU/ml calculagted from the GoStix Value (GV, ng/ml p24)

1. To calculate the actual IFU/ml for an unknown stock, a reference virus (a virus stock for which the IFU/ml is known) must first be tested to obtain both an infectious unit value as well as a GV.
2. Calculate the IFU/GV ratio for the reference virus.
3. Analyze the unknown sample using Lenti-X GoStix Plus to obtain the GV (ng/ml p24).
4. Perform calculations to determine your IFU/ml (see Table below). NOTE: To be able to accurately calculate IFU/ml for an unknown virus using a reference virus, the unknown virus and reference virus must be produced using similar protocols.

Formula: GV (unknown) x (IFU/ml)/GV (reference) = IFU/ml (unknown)
Example from Table I, above: 850 ng/ml x 8,197 IFU/ng = 7.0 x 106 IFU/ml