Applications of FT-IR spectrometry to plasma contents analysis and monitoring

We devoted efforts to develop an analytical method of plasma able to provide both a high sensitivity and a global overview of its biomolecular contents along with the variations of these ones. Among candidates, transmittance FT-IR spectrometry has proved to be highly efficient. It has been used to analyze plasma micro samples (50 mul) using an iterative process. Results in accordance with clinical data were obtained from a single FT-IR spectrum for the following biomolecules: amino-acids, fatty acids, albumin, glucose, fibrinogen, lactate, triglycerides, glycerol, urea, alpha(1)-antitrypsin, alpha(2)-macroglobuhn, transferin, Apo-A(1) Apo-B, Apo-C-3, IgA, IgD, IgG(1), IgG(2), IgG(3), IgG(4), IgM, haptoglobin, and alpha(1)-acid glycoprotein. Moreover, cholesterol contribution may be determined on the same IR spectrum. Therefore, as only nucro samples are necessary, high frequency blood analysis become available. This method was used to monitor inflammatory processes related to given metabolic stresses. Moreover, FT-IR spectrum constitutes a "metabolic photography" of the subject, allowing classification between metabolic groups (pathologic or others). It was used on difference spectra in order to raise "signal to noise" ratio by elimination of the unvarying spectral contribution. Among others, it allowed to uncover overtraining in high-level sportsmen several weeks before any physiologic or clinical symptom occurred.