- In the present study, Fourier-transform infrared microspectroscopy (micro-FTIR) was applied for the analysis of human plasma samples in order to detect spectral parameters, which might serve as biomarkers for monitoring and identification of leukemia patients. Samples of plasma were obtained from healthy and patient persons suffering from chronic lymphocytic leukemia and analyzed by micro-FTIR. The results show that spectral peaks at 1056, 1270 and 1592 cm −1 appearing in all examined samples obtained from healthy persons were significantly reduced in all tested patient samples. Cluster analysis of the obtained spectra at these specific regions provided excellent classification of the healthy and the patient samples which correlate completely with clinical data. These parameters could be used as a basis for developing a spectral method for the detection and identification of this type of human leukemia.