Dawn heleos 8 mals detector

The molecular weight of the aggregates was determined using SEC in combination with multi-angle light scattering (MALS). SEC-MALS was performed using an Äkta Explorer 100 instrument (GE Healthcare) equipped with a Yarra SEC-4000 column (Phenomenex), an Optilab T-Rex refractive index (RI) detector (Wyatt) and a DAWN HELEOS 8+ MALS detector (Wyatt). The samples were analyzed at room temperature (RT) using 0.1 μm filtered PBS (pH 7.0).

SEC-MALS analysis was performed using an Agilent 1260 HPLC system (Agilent, USA) and a Superdex 75 10/300 SEC column (Cytiva, USA) connected in series to an Optilab T-rEX differential refractometer (Wyatt Technology Co., USA) operating at 25 °C and a Dawn Heleos 8 MALS detector (Wyatt Technology Co., USA) equipped with a He–Ne laser (λ = 660 nm). The column was eluted at a flow rate of 0.5 mL/min with 50 mM ammonium formate pH 5. All data were acquired and processed using ASTRA 7 software (Wyatt Technology Co., USA).
Native esterified wine and celery RG-II monomer and dimer (1–2 mg) were dissolved in ultrapure water and filtered using 0.45 μm nylon Costar® Spin-X® centrifuge tube filters (Corning, USA). The injection volume was 100 μL and a minimum of three injections for each polysaccharide were performed. The dn/dc value for RG-II was calculated by analysis of the purified native celery monomer. Different amounts of monomer (1.0, 0.5, 0.2, and 0.1 mg) were injected, and the dn/dc value was obtained on-line assuming 100% mass recovery for the peak of interest. The calculated dn/dc value (0.122 ± 0.003 mg/mL) was used for all RG-II analyses.