Figure 1
Example of FTIR cell imaging using different spatial resolutions. (a) 6.25 µm × 6.25 µm spatial resolution obtained with a Perkin–Elmer Spotlight 300 FTIR imaging system (detector dimension 25 µm × 25 µm with a 4× numerical magnification). 64 scans were required to obtain high SNR (= 1324), which is sufficient for further data treatments. (b) 2.66 µm × 2.66 µm spatial resolution obtained with a Bruker Hyperion 3000 imaging system (detector dimensions 40 µm × 40 µm with a 15× numerical magnification). 128 scans were required to obtain sufficient SNR (= 527). (c) The same instrumentation as for (b) but with a 36× numerical magnification. The SNR obtained was only 21 and does not permit further spectral data treatment. All FTIR images have been normalized in intensity on a common scale (a.u. of spectrometer) after integration of the 1700–1600 cm−1 spectral interval (amide I) for every pixel. |