ATR FT-IR Imaging of Live Cells

Rather than culture directly onto an ATR crystal, it has been shown to be possible to approach fixed cells with a slide-on ATR accessory [116]. The advantage of this approach is that it has the potential to study cells by the ATR mode in many different environments and, indeed, an example was shown with fixed cells immersed in water having been imaged. Nevertheless, it remains an important step to apply this methodology to image live cells. 

2 Transmission Mode FT-iR imaging of Live Cells in Microfluidic Devices 

Although live adherent cells can be studied upon incubation in medium at an ATR surface as shown, it would be an attractive option to combine the power of FT-IR imaging with microfluidics in order to study cells in controlled but changing environments. There are two potential approaches to this, one is to construct a microfluidics platform directly on top of an ATR crystal, and the other is to design a microfluidics system that is suitable for transmission mode measurements. The transmission mode remains an attractive option because of the potential for improved SNR. As with all transmission mode measurements involving aqueous systems, care must to be taken to ensure very 

FT-IR images and extracted spectra from the experiment. (Kazarian and Chan [115], 1940, Reproduced by permission of The Royal Society of Chemistry.) 

however, should be taken when using thick IR windows for imaging applications. Although the liquid cell is commonly used in single-spectrum measurements, refraction of light at the IR windows of the liquid cell may have undesirable effects on the spatially resolved spectra in an imaging measurement [117-119]. 

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