Miniature diamond-anvil cells for FTIR-microspectroscopy of small quantities of biosamples

Abstract

Fourier transform infrared (FTIR) spectroscopy techniques and data analyses have become widely available, are easy to use, and are convenient for studies of various biosamples, especially in biomedical science. Yet, cultivation of cells and purification of cell components are costly, often methodically challenging, and time and labor consuming. Therefore, reduction of the sample amount is of high value. Here we propose a novel method for the analysis of small quantities of biosamples by FTIR-microscopy of dry films using a diamond-anvil cell (DAC). This approach allows us to decrease the sample volume at least a hundred times compared to that for a high-throughput screening device (HTS-XT, Bruker, Germany), while still obtaining homogeneous films, acquiring qualitative spectra, and using a conventional 15× objective instead of an ATR-objective. Both FTIR methods were applied for analyses of human colorectal cancer cell lines SW480 and SW620 cultured under hypoxic conditions to estimate the strengths and weaknesses of each approach. FTIR absorption spectra acquired by both methods were compared and no significant spectral differences were detected. It was shown that FTIR-microscopy of films on the DAC can be used for evaluation, screening, discrimination and identification of biochemical markers in biosamples like cells. We conclude that the DAC can be transferred to other biosamples like tissues, biofluids, their components and extracellular matrix, and is especially valuable when the available quantities of biosamples are limited.

Infrared spectroscopy of live cells from a flowing solution using electrically-biased plasmonic metasurfaces

“…[58][59][60] Without full adherence to the IRE, the reflected spectra suffer from poor signal-to-noise ratio; external mechanical force application may be required to improve the spectra. 61,62 Ensuring close proximity of live cells to the IRE is even more challenging for non-adherent cells, such as normal and cancerous leukocytes and red blood cells. 60,63 Special chemical and structural modifications of the substrate are needed to keep such cells in good contact with the sensor, 64 including functionalization of the sensor with appropriate antibodies ("antibody chips").…”

Prediction of type 1 diabetes with machine learning algorithms based on FTIR spectral data in peripheral blood mononuclear cells

“…Cell samples from 50 patients (24 T1D and 26 individuals without impaired glucose tolerance) were thawed at room temperature, and small amount of sample (∼3 μL) was pipetted onto diamond anvil cell and FTIR spectra registered as in ref. 50. All spectra were recorded with Vertex 70 spectrometer coupled with the Hyperion 2000 microscope equipped with a 15× IR objective (all from Bruker, Germany) in a range of 4000–600 cm −1 by coadding 32 individual scans.…”

“…Reduction of the sample amount is of high value and therefore was developed a FTIR-micro spectroscopy technique of dry films using a diamond-anvil cell (DAC) that allows to decrease the sample volume at least a hundred times compared to that for a high-throughput screening device (HTS-XT, Bruker, Germany). 50 Studies of human colorectal cancer cell lines SW480 and SW620 showed that this approach can be used for evaluation, screening, discrimination, and identification of biochemical markers in biosamples like cells, tissues, biofluids, their components and extracellular matrix especially when the available quantities of sample is limited. In this study we used a FTIR-micro spectroscopy technique with DAC to find/detect the possible metabolic fingerprints of autoimmune diseases in the peripheral blood mononuclear cells (PBMC) of patients, as well as to find out whether the data obtained by FTIR and machine learning algorithms can be used to predict the presence of an autoimmune component.…”

Crypthecodinium cohnii Growth and Omega Fatty Acid Production in Mediums Supplemented with Extract from Recycled Biomass

“…FTIR is a rapid method, particularly used for monitoring the relative content of each macromolecular component under varying growth conditions [28][29][30][31]. FTIR spectroscopy of C. cohnii biomass was used to evaluate the growth medium-induced production of lipids/FA and PUFAs.…”