Sample storage temperature effects on blood serum ATR-FTIR spectra

Introduction. FT-IR spectroscopy is nowadays considered a useful tool for investigating blood serum samples in many applied fields. The use of this technique in the clinical setting is hampered by the need to carefully control sample preparation and storage methods. The sample storage temperature represents a factor that can surely influence the FT-IR spectroscopy results. For this reason, we investigated blood serum samples stored at different temperatures.

Methods. FT-IR spectra were acquired from blood serum samples from healthy human donors stored at two different temperatures (4°C and -80 °C) using a Universal Attenuated Total Reflection (UATR) accessory and a Perkin-Elmer Spectrum One spectrometer equipped with a DTGS (Deuterated Triglycine Sulfate) detector. Multiple acquisitions of spectra were done, and statistical criteria were applied to monitor and compare them. The acquired spectra were analysed using deconvolution procedures, difference spectra, and ratiometric analysis

Results. The adopted data analysis procedures evidenced some spectral changes induced by different storage temperatures. In particular, spectral position, signal intensity, and band shape were modified. The preliminary results highlighted modifications of the lipid and protein components of blood serum samples.

Conclusions. The reported results indicated that well-controlled sample handling procedures are required to use FT-IR spectroscopy in clinical environments.