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The Use of Capillaroscopy and Aggregometry Methods to Diagnose the Alterations of Microcirculation and Microrheology in Diabetes
Published in Andrey V. Dunaev, Valery V. Tuchin, Biomedical Photonics for Diabetes Research, 2023
Andrei E. Lugovtsov, Yury I. Gurfinkel, Petr B. Ermolinskiy, Anastasia A. Fabrichnova, Alexander V. Priezzhev
To measure such aggregation parameters of blood as the characteristic time of cell aggregation, amplitude of aggregation, and aggregation index (AI), cuvettes of the first type were used (Figure 3.2a). The cuvette is small, flat, 0.5 cm in diameter, containing a thin metal stirring rod that can be rotated by an external magnetic field generated inside the thin reservoir of whole blood to mix its contents. Whole blood (8 μl) was placed into the cuvette using a micropipette.
Pre-Clinical In-Vivo and In-Vitro Methods For Evaluation of Anti-Alzheimer’s Drugs
Published in Atanu Bhattacharjee, Akula Ramakrishna, Magisetty Obulesu, Phytomedicine and Alzheimer’s Disease, 2020
Shilpa A. Deshpande, Niraj S. Vyawahare
Procedure: The treated animals are decapitated, and the brains are removed quickly and placed in ice-cold saline. Frontal cortex, hippocampus, and septum are quickly dissected out in a Petri plate chilled on crushed ice. The tissues are weighed and homogenized with tissue a homogenizer in 0.1 M phosphate buffer (pH 8). An aliquot (0.4 ml) of the homogenate is added to a cuvette containing 2.6 ml phosphate buffer (0.1 M, pH 8) and 100 µl of DTNB reagent. The contents of the cuvette are mixed thoroughly, and the basal absorbance is measured at 412 nm in a spectrophotometer. An aliquot (20 µl) of substrate, i.e., acetylthiocholine is added, and the change in the absorbance per minute is determined.
Fluorescent Analysis Technique
Published in Victoria Vladimirovna Roshchina, Fluorescence of Living Plant Cells for Phytomedicine Preparations, 2020
Victoria Vladimirovna Roshchina
LSCMs allow the use optic slices without damage of the objects not more than 1 mm in thickness, especially if one uses microscopes with objectives, that are located below the sample (the inverted variant of microscopes). In the latter type of microscopy, it is also possible to take advantage of special glass cells-cuvettes, usually eight units (each volume about 1 cm3), into which a user puts the samples, both solid and liquid, and perceives images from lower side of the object. For special studies, it is better to prepare slices mechanically for tissue imaging. For single cells, such as pollen of seed-bearing plants and spores (vegetative, not sexual, unlike male cell of pollen) of spore-bearing species, it is not recommended to enclose them with a cover glass if you want to see their development, and, as well as subject slides, you may use the above-mentioned glass cells-cuvettes. As well as research devoted to particularly to plant pharmaceuticals from land areas, LSCM is used on red algae from seaweed farms near the Caribbean entrance of the Panama Canal (de Vega et al. 2016). The same technique gives information about the fluorescence intensity of the objects at characteristic wavelengths. Some confocal apparatuses allow to receive photo on the display for analyzing the images with optical probes, so-called ROI (ROI = research of interest), on various parts of the sample.
IgG antibodies mediated gold nanoparticles conjugated to methotrexate as targeted chemotherapy for lung cancer
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2023
Asad Syed, Abu Baker, Mohamed Mohany, Abdallah M. Elgorban, Mohd Sajid Khan, Salim S. Al-Rejaie
Bioconjugation of as-synthesised IgGAuNPs was performed to attach the FDA-approved cancer chemotherapeutic drug MTX. To join the free amino group of MTX with the carboxylate group of the IgG antibodies, the activator and coupling agent 1-Ethyl-3-(3-dimethyl) carbodiimide (EDC) was utilised [18]. The 5 ml reaction mixes included 250 µg of MTX, 3 ml of IgGAuNPs, and 50 mM HEPES buffer (pH 7.6). At the end of the three-hour incubation period at 30 °C, 5 mM of EDC was added in aliquots. A DLS particle size analyser (Model ZEN3600, Malvern Instrument Ltd., Malvern, United Kingdom) was used to estimate the average particle diameter of IgGAuNPs and MTX-IgGAuNPs. The samples were collected in a 1.5 ml limited-volume disposable cuvette for analysis. The sample was diluted to 0.5% (w/v) in de-ionized water. After sonicating the particles for one minute, the average particle size was calculated by measuring a single sample in triplicate. Surface charges of IgGAuNPs and MTX-IgGAuNPs were measured using a Zeta Sizer Nano-ZS, Model ZEN3600 (Malvern Instrument Ltd, Malvern, UK).
Avoiding artifacts in liposome leakage measurements via cuvette- and liposome-surface modifications
Published in Journal of Liposome Research, 2022
Philipp Grad, Víctor Agmo Hernández, Katarina Edwards
Cuvettes are inevitable elements in spectroscopic experiments and can be composed of various materials, such as quartz or different polymers. For leakage experiments, the excitation and emission wavelength of CF are in the visible range and therefore most cuvette materials are deemed suitable. A preference for quartz can be explained by its superiority with regard to the wide range of optical transmission and solvent compatibility. Furthermore, quartz cuvettes can be reused. Plastic cuvettes, made from, for example, polystyrene (PS) and poly(methyl methacrylate) (PMMA), are often limited to the visible range and to aqueous solutions but offer the advantage of being cheap. The cuvette materials also differ in their surface properties and temperature resistance (Overway 2017). The influence of the cuvette material on the actual measurements has to date received only limited attention. Predotova et al. (2011). reported on the effects of the cuvette surface material on gas concentration measurements. Adhesion effects lead to varying results when using different cuvette materials (Predotova et al.2011). The physical properties of cuvette surfaces have also been shown to affect the measurement of enzyme activity, as studied by Cattoir et al. (2013).
Full-length TDP-43 and its C-terminal domain form filaments in vitro having non-amyloid properties
Published in Amyloid, 2021
Claudia Capitini, Giulia Fani, Mirella Vivoli Vega, Amanda Penco, Claudio Canale, Lisa D. Cabrita, Martino Calamai, John Christodoulou, Annalisa Relini, Fabrizio Chiti
Ct and FL TDP-43 aggregates, prepared as described above and then diluted to a concentration of 0.4 mg/mL (29.2 µM and 8.2 µM for Ct and FL TDP-43, respectively), were incubated at 25 °C for 5 min and an aliquot of 60 µL of each sample was mixed with 440 µL of 25 mM NaH2PO4 buffer at pH 6.0 containing 25 µM ThT. We decided to use the same mass concentration for FL and Ct TDP-43 aggregates, rather than the same molar concentration, as we considered that having both samples with a similar “protein mass” reduced the possibility of misinterpreting the data obtained. The resulting fluorescence was measured at 25 °C using a Perkin-Elmer LS 55 spectrofluorimeter (Waltham, MA), using excitation and emission wavelengths of 440 and 450–600 nm, respectively. A 2 × 10 mm quartz cuvette was used. For FL TDP-43 aggregates, the ThT fluorescence measurements were also collected after 1, 2, 5, 6, 7, and 8 days from the beginning of dialysis when the aggregates start to form, keeping the original sample at 0.4 mg/mL protein at 37 °C between the different measurements. The experiment was repeated using HypF-N aggregates, prepared as described above and diluted to a concentration of 0.25 mg/mL at 25 °C for 5 min before the assay.