Uv vis spectrophotometer model 8453

The radical scavenging activities of the seed extracts against the ABTS radical cation were determined according to a method described previously [34 (link)], with some modifications. The ABTS stock solution was prepared by reacting ABTS reagent with manganese dioxide as the oxidising agent. Before analysis, 10 mL of ABTS stock solution was diluted with 25 mL of 0.325 M phosphate buffer and 65 mL of Milli-Q water. An aliquot of each extract (0.05 mL) was mixed with 0.5 mL 0.325 M of phosphate buffer and 1.0 mL of diluted ABTS radical cation solution, and 0.45 mL Milli-Q water was added, to give the final volume of 2 mL. The mixture was shaken and left in the dark for 1 h. The absorbance was measured at 734 nm (UV–Vis spectrophotometer; model 8453; Agilent Technologies, Santa Clara, CA, USA). A lower absorption of the reaction mixture indicates higher free radical scavenging activity. The absorbance of the control was achieved by replacing the seed sample with methanol. The measurement was compared to a standard curve of a Trolox solution, and the radical scavenging activity is expressed as mg TE/g DW.

Each xerogel sample was loaded by sorption in 2 mL of 0.75 wt% MTZ solution, followed by freeze-drying. The experiments of drug release were performed in citrate–phosphate buffer (pH 4.5, 100 mM) and MSVF, at temperatures of 25 and 37 °C. The MTZ-loaded hydrogels were immersed in 50 mL of buffer solution. At specific time intervals, samples of 200 μL were withdrawn and replaced with equal volumes of fresh medium. The MTZ concentration was determined by recording the absorbance at 320 nm in an UV–Vis spectrophotometer model 8453 (Agilent Technologies, Shangai, China), and subsequently interpolating the value in a calibration curve.

The absorbance of the samples was measured at 633 nm with a Model 8453 UV–VIS spectrophotometer (Agilent Technologies, Santa Clara, CA, USA). The surface charge and hydrodynamic diameter of the particles were determined using a Zetasizer Nano ZS (Malvern Instruments Ltd., Worcestershire, UK). DLS measurement was performed at 37 °C in backscattering mode (detector fixed at 173°) using a 633 nm He-Ne laser. Samples were measured in a reusable quartz cuvette (type PCS1115 6G; Malvern Instruments Ltd., Worcestershire, UK). Measurement of zeta potential was performed under similar conditions. DTS1070 disposable cuvettes were used (Malvern Instruments Ltd., Worcestershire, UK). The measurement data were evaluated using software provided by the manufacturer, and statistical data and graphs were created and evaluated with Origin 9.0 (OriginLab) and Microsoft Excel 2013 software. DLS measurements were performed weekly for a period of 6 weeks to determine colloidal stability. Samples were stored at 2–8 °C.

Full-length PSD-95, CC-PBM from SynGAP, and CTD2A or CTD2B were mixed at 1:1:1 ratio in 20 mM tris, 150 mM NaCl, at pH 7.4 buffer with each protein at a final concentration of 20 µM. Samples were equilibrated in polypropylene microfuge tubes at room temperature (25 °C) for 5 min before measurements. Transmittance of aliquots removed from the incubation was measured at 550 nm in quartz cuvettes with a 1 cm path length using an Agilent model 8453 UV-Vis spectrophotometer. Turbidity was calculated as percentage of transmittance. The time-dependent turbidity formation seen with CTD2A was slower than condensate formation induced by the ternary mixture. As such, we can remove urea from CTD2A for condensate formation experiments without the appearance of CTD2A precipitation.