Molecular bonds with an electric dipole moment that can change by atomic displacement owing to natural vibrations are IR active. The use of Fourier transform IR (FTIR) spectroscopic techniques for the nondestructive analysis of biological specimens is a rapidly expanding research area, with much focus on its utility in cytological and histological diagnosis through the generation of spectral images 1, 2. Example results are presented on the use of IR spectra combined with multivariate data processing. A typical experiment can be completed and analyzed within hours. After acquisition, data processing consists of a sequence of steps including quality control, spectral pre-processing, feature extraction and classification of the supervised or unsupervised type. We describe a protocol for collecting IR spectra and images from biological samples (e.g., fixed cytology and tissue sections, live cells or biofluids) that assesses the instrumental options available, appropriate sample preparation, different sampling modes as well as important advances in spectral data acquisition. This manuscript brings together as coauthors some of the leaders in this field to allow the standardization of methods and procedures for adapting a multistage approach to a methodology that can be applied to a variety of cell biological questions or used within a clinical setting for disease screening or diagnosis. One of the major difficulties in the field has been determining a consensus on spectral pre-processing and data analysis. Because such images are constructed from fingerprint spectra, the notion is that they can be an objective reflection of the underlying health status of the analyzed sample. Although not strictly microscopy in the conventional sense, it allows the construction of images of tissue or cell architecture by the passing of spectral data through a variety of computational algorithms.

It enables the nonperturbative, label-free extraction of biochemical information and images toward diagnosis and the assessment of cell functionality.

IR spectroscopy is an excellent method for biological analyses.

Water ftir spectrum