The present invention provides novel methods for determining whether a compound influences a phase in the life cycle of a virus comprising providing a cell with the compound and with at least a fragment of the virus sufficient for performing the phase and determining whether the phase is influenced in the cell, the cell comprising a nucleic acid encoding an adenovirus early protein or a functional part, derivative and/or analogue of the adenovirus early protein. In another aspect, the invention provides the use of a cell, the cell comprising nucleic acid encoding an adenovirus early protein, for screening a library of compounds for the presence of a compound capable of influencing a phase in the life cycle of a virus capable of entering the cell. The invention also provides novel methods for identifying a compound with antiviral activity comprising providing a cell with at least a fragment of a virus, the fragment capable of performing a step in the life cycle of the virus, providing the cell with a compound and determining whether the compound is capable of influencing the step in the life cycle of the virus, wherein the cell comprises a nucleic acid encoding an adenovirus early protein or a functional part, derivative and/or analogue of the adenovirus early protein.