Biology subjects

Baranska, M.

Publications and source records attributed to Baranska, M..

4 recordsLinked to original sources

bioRxiv2025

Cell-in-Water: measurements using Optical Photothermal Infrared spectroscopy

Conventional Fourier transform infrared absorption spectroscopy (FT-IR) allows for measurements of spatial resolution comparable to a whole cell size, which are performed on dried cells to avoid water interference. However, such conditions can disrupt the native morphology and chemical composition of cells, whilst not providing for crucial sub-cellular biochemical detail. Pump-probe Optical Photothermal Infrared (O-PTIR) Microscopy offers high-resolution measurements of cells, but the challenge of measuring cells without disturbing their morphology remains. To overcome this, we developed a protocol enabling O-PTIR measurements of cells in aqueous environments using a silicone-sealed microchamber, which allows imaging of live cells in 2 {micro}l of buffer for up to 4 hours. Analysis of O-PTIR data obtained from hydrated and dehydrated cells confirms that hydrated conditions better preserve subcellular organization, as evidenced by secondary structure changes of proteins. We also propose a step-by-step algorithm that can improve image quality through ratiometric analysis, histogram assessment, and the application of RGB overlays. This approach allows for visualization of multiple subcellular components, such as the nucleus or lipid droplets. Trough the combination of "sandwich" sample configuration and O-PTIR, we offer a promising strategy to advance O-PTIR measurements of cells in water, which have long been considered a major challenge. A direct comparison of O-PTIR with Raman microscopy highlights the complementarity of these two techniques and similar spatial resolution.

biophysics↗

bioRxiv2025

Quantifying lipids in human cells using Raman spectroscopy

Withdrawal statementThe authors have withdrawn this manuscript because they have identified several inaccuracies that require further refinement. Therefore, the authors do not wish this work to be cited as a reference for the project. If you have any questions, please contact the corresponding author.

biophysics↗

bioRxiv2025

From Single Molecular Detail to Subcellular Dynamics: Real-Time Kinetics Study of dPA Uptake with Raman-based Spectroscopy

Real-time observation of cellular transformations at the subcellular level provides insight into the dynamic biochemical processes underlying cell function and disease. However, many challenges remain in developing methods to analyze metabolic transformations in cells quantitatively. Our study applies Raman spectroscopy (RS) and stimulated Raman scattering (SRS) to link single-molecule resolution with cellular-scale lipid turnover tracking. Using HL-60 cells as a model, we monitor the uptake kinetics of deuterated palmitic acid (dPA), a marker of de novo lipogenesis, from the first minutes to hours. SRS enables microscopic, high-temporal-resolution visualization of dPA incorporation across entire cell volumes, capturing both its distribution and uptake rate. Complementary RS measurements identify distinct metabolic phases: rapid incorporation into pre-existing lipid droplets (LDs) followed by the emergence of new, partially unsaturated LDs associated with cytochrome-linked metabolism. Statistical and spectral analyses reveal cell-to-cell heterogeneity, emphasizing the complexity of lipid metabolism at both the cellular and subcellular levels. By integrating SRS and RS data into time-dependent kinetic profiles, we establish a unified submicron-to-cellular model of fatty acid metabolism. This multi-resolution spectroscopic approach demonstrates how real-time, label-based tracking can uncover dynamic metabolic heterogeneity, advancing understanding of the fatty acid uptake and metabolism in the microscale.

cell biology↗

bioRxiv2024

A unique Tandem RAman Microscopy (TRAM) integrating spontaneous and coherent Raman scattering offers integrated data analysis to improve optical biosensing

We provide Tandem RAman Microscopy (TRAM), a cutting-edge multimodal microscope that integrates the methods of Stimulated Raman Scattering (SRS), Coherent anti-Stokes Raman Scattering (CARS), and spontaneous (Resonance) Raman Scattering ((R)RS). The device facilitates sequential Continuous Wave (CW) driven RS imaging to collect full spectra from every sample location and rapid pulsed-wave-driven SRS-CARS scanning at specific wavenumbers, offering a reliable and efficient analytical tool. The fingerprint spectral region can be included in the spectral imaging capabilities of CARS and SRS. Data collected from a sample area using several techniques can be integrated and analyzed, significantly increasing reliability and predictions. We analyzed the in vitro model of nonadherent leukocytes (LC) to illustrate the capabilities of this unique system, emphasizing the benefits of measuring the same sample with three different Raman techniques without having to transfer it between microscopes. Data fusion allowed for the correct classification of two subtypes of LC based on the partial least squares (PLS) discrimination, increasing the prediction accuracy from approximately 83% in the case of textural and morphological data (SRS) to 100% when combined with spectral data (SRS and RS). We also present RRS images of LC labeled with astaxanthin, and reference data from SRS and CARS microscopy. Additionally, polystyrene beads were investigated as a non-biological material. The advantages of each Raman technique are utilized when (R)RS, SRS, and CARS are combined into a single device. This paves the way for dependable chemical characterization in a wide range of scientific and industrial fields.

biophysics↗