Patent ID: 8603736

Claim:
A method for determining whether an HIV population is resistant to an HIV entry inhibitor, comprising: (a) contacting a plurality of HIV viral particles with a cell in the presence of an HIV entry inhibitor, wherein the cell expresses a cell surface receptor to which the viral particles bind, and wherein the cell or the viral particle comprises an indicator nucleic acid that produces a detectable signal when the viral particle enters into the cell, (b) collecting data points that measure entry of the HIV population into the cell by measuring the amount of the detectable signal produced by the cell in the presence of varying concentrations of the HIV entry inhibitor; (c) generating a log-sigmoid inhibition curve comprising the data points showing the maximum inhibition percentage for the HIV population; and (d) comparing the maximum inhibition percentage of the inhibition curve of step (c) to the maximum inhibition percentage of a log-sigmoid inhibition curve for a reference HIV population; and (e) determining that the HIV population has reduced susceptibility to the HIV entry inhibitor if the maximum inhibition percentage observed for the HIV population is lower than the maximum inhibition percentage observed for the reference HIV population.