Ultraviolet uv spectrophotometer

Around 2 ml venous blood was taken from each subject after their admission, and the blood samples were reserved at −20°C for later usage. Genomic DNAs, extracted from peripheral blood samples with TIANamp Genomic DNA kit (TIANGEN Biotech, Beijing, China), were treated by 1% agarose gel electrophoresis. The DNA samples were qualified, when their A260/A280 ratio was within the scope of 1.7 ~ 1.9, after examination by ultraviolet (UV) spectrophotometer (Thermo). Integrity of the DNA samples was confirmed adopting 0.8% agarose gel electrophoresis, concentration of DNA in each sample was adjusted to >20 ng/μL. With primers detailed in Table S1, SNPs of GAS5 (ie, rs2067079, rs6790, rs17359906, and rs55829688), MIR‐21 (ie, rs1292037 and rs13137), and mTOR (ie, rs2295080, rs2536, rs11121704, and rs1034528) were genotyped with mass spectrometry analysis platform (model: MassARRAY, Sequenom corporation). The SNPs were genotyped by two operators through double‐blind manner, and >10% of the samples were randomly screened to re‐identify their genotypes. The genotyping results were acceptable only when results of two examinations were consistent.

The volumetric concentration of PS in EPS extractants was determined by the improved phenol-sulfuric acid colorimetric method, using glucose as the standard [16 (link)]. Proteins and humic acids were measured by a modified Lowry method [17 (link)]. The above parameters were quantified with an Ultraviolet (UV) spectrophotometer (Thermo Fisher Scientific, CN), and the concentrations of PS, PN, and HA were normalized to the biomass in units of mg per g dry cells.
EPS composition was analyzed by fluorescence spectroscopy (F7000, Hitachi, Japan) by three-dimensional excitation-emission matrix (3D-EEM) scanning. The excitation wavelength (Ex) varied in 2 nm increments from 200 to 400 nm, and the corresponding emission wavelength (Em) varied in 2 nm increments from 200 to 550 nm. The scanning speed for all measurements was set to 30,000 nm min⁻¹, and the spectral recording of Milli-Q water was used as a blank. The software package Origin 2021 was used to process the 3D-EEM data.