FTIR spectra showing changes in absorbance when cells are infected with poliovirus. Spectra in the wavelength region of 650 - 3600 cm-1 show the absorbance of BGMK cells infected with different PV1 titers 101 - 104 PFU/ml at 8 h.p.i. Uninfected cells served as a control. Nine regions were chosen by the PLS model as the most informative for detecting changes in cell components following virus infection. The different colors represent the mean spectra of the samples.