Mid-Infrared (IR) spectroscopy allows for non-destructive and label free analysis providing molecular specific information. This technique can thus be successfully applied in microbiological and biomedical research. IR spectroscopic imaging is an advantageous complimentary tool to established histological analysis. However, IR spectroscopy has certain limitations: the spatial resolution of IR microscopic imaging cannot be better than a few micrometers due to the diffraction limit in far-field microscopy and IR spectroscopy cannot provide information on an elemental level. The first limitation can be solved through the application of recently developed near-field imaging techniques such as phothermal induced resonance (PTIR). The second limitation can be overcome when an additional technique complementary to IR spectroscopy is used too and the combined data-sets are jointly analysed. ^The first experimental part of this thesis is devoted to the characterization of a custom made PTIR system and its application to the measurements of various biological samples. The second experimental part is devoted to the combined image analysis of histological samples using commercially available techniques such as Fourier transform Infrared (FTIR) spectroscopy and laser ablation inductively coupled mass spectrometry (LA-ICP-MS). In the first part of the work time-resolved PTIR spectroscopic measurements are reported for the first time on the example of a biopolymer (poly-L-lysine, PLL) 200 nm thick film. PLL films can adopt different secondary structures depending on its water content, which can be adjusted through temperature in an atmosphere of controlled humidity. A controlled temperature ramp of the sample caused changes in the amide I band of the PLL. Those changes were detected using PTIR time resolved measurements. ^The achieved acquisition time of one PTIR spectrum is 15 s. Control analysis using a commercial FTIR microscope corroborated the spectroscopic results. Further, the PTIR performance was characterized regarding AFM tip aging during prolonged measurements of the polymer polystyrene (PS) and biological samples (cells and tissues). It was shown, that after the prolonged measurements of PS have no notable affect on the PTIR performance. However, a notable decrease in PTIR sensitivity was observed after several measurements of biological samples. A method for in-situ controlling aging if the AFM tip was proposed. The AFM tip aging was judged by following the signal intensity of a band s(Si-CH3) associated with stable impurities of the gold coated tip. The proposed method was successfully employed during the measurements of biological samples (cells and tissues). PTIR spectroscopic and imaging measurements of individual E. ^Coli bacteria consisting of aggregated proteins (horseradish peroxidase) as inclusion bodies (IBs) were performed. The average secondary structure of the IBs found to be different from the host bacteria. A method for the quantitative analysis of the present IBs was proposed. PTIR and FTIR spectra of dead (apoptotic) and viable regions in a histological tumor section were acquired and analysed. The results of the near-field analysis agree with the far-field micro-spectroscopic measurements. In particular, changes in protein secondary structure and nonlinear properties in the absorption of IR radiation by condensed nucleic acids were observed. Further, using the PTIR technique individual dead (apoptotic) and viable mammalian cells were characterized. Two types of apoptotic cells were discriminated. For some cells protein secondary structure at nuclei and cytoplasm regions appeared to be different. Other cells had no notable differences in the overall protein conformation. ^In both kinds of apoptotic cells the decay of the band related to nucleic acids (C-N-C stretch of ribose-phosphate skeletal vibrations in nucleic acids) was observed. Viable (control) cells demonstrated no significant alterations in the overall protein secondary structure at nuclei and cytoplasm regions. Additionally, the overall protein conformation in nuclei region for apoptotic and control cells were found to be different. In the second part of the work combined image analysis for discrimination and characterization of biological tissues (tumor and ischemic brain) was performed. Combined analysis of the tumor demonstrated statistical correlations between elemental and molecular chemical maps. Additionally, the combination of data from the two techniques (FTIR and LA-ICP-MS) facilitated an improved cluster analysis and allowed discrimination of different stages of apoptosis within a tumor tissue. ^Besides, the combined (multi-sensor) analysis helped to characterize different degrees of cellular death within different tumor samples. During the multi-sensor analysis of thin cuts of ischemic rat brain partial least squares discriminant analysis (PLS-DA) and random decision forest (RDF) classification algorithms were applied and their performance was compared. As a result, different tissue types were distinguished. The performance of classification models built on the combined dataset was compared with the classification results based on the individual datasets. Multi-sensor analysis again improved classification. Here different tissue types such as white and gray matter, as well as stroke region and its surroundings could be differentiated more efficiently. Furthermore RDF classification appeared to me more precise than PLS-DA. ^The results, presented in this thesis demonstrate the capabilities and advances of near- and far-field IR spectroscopy and spectroscopic imaging applied to analysis of biological samples. Further, the results demonstrate that the multi-sensor combined analysis incorporating FTIR and LA-ICP-MS imaging facilitates an improved multivariate analysis and thus deeper understanding of biochemical processes.