. 2006 Jun;80(12):6146–6154. doi: 10.1128/JVI.02628-05

TABLE 2.

Selection of resistance to NNI-1 through sequential passaging

Passage^a	NNI-1 IC₅₀^b (μM)	NS5B mutations^c	No. of molecular clones with indicated resistance mutation/ total no. of clones^e
Passage^a	NNI-1 IC₅₀^b (μM)	NS5B mutations^c	WT^d	419M	423T	423I	423V	482L
Untreated P9	0.2	WT	10/10
Treated P3	0.2	WT	17/18					1/18
Treated P5	2	L419M, M423T		7/19	9/19	3/19
Treated P9	9	L419M, M423T	1/28	8/28	14/28		3/28	2/28

P, passage number. All passages were carried out either in the absence (untreated) or in the presence of 4 μM of NNI-1.

The IC₅₀ values represent the averages of duplicate results from one single experiment.

Direct sequencing from PCR products, representing the major population (in one-letter amino acid code).

WT indicates no mutation or no known mutation related to HCV polymerase drug resistance.

Number of molecular clones spanning the entire NS5B coding region showing a particular mutation at any of the NNI-1 identified resistance amino acid residues compared to the total number of molecular clones analyzed for each sample.