Dawn heleos 2

The Mw of Fuc-S was determined by high-performance size-exclusion chromatography (HPSEC) equipped with a multi-angle laser light scattering (MALLS) detector (DAWN HELEOS Ⅱ, Wyatt Technology Co., Santa Barbara, CA, USA) and an Optilab T-rEX differential refractive index detector (RID) in a Waters 2695 HPLC system (Wyatt technology, Santa Barbara, CA, USA). Several columns were used, including a guard column, Shodex OHpak SB-G (50 mm × 6 mm, Shodex China Co., Ltd., Shanghai, China), and Shodex OHpak SB-806 HQ (300 mm × 8 mm, Shodex China Co., Ltd., Shanghai, China). An aqueous solution of NaNO₃ (0.1 M) was prepared as the mobile phase. The Mw was calculated using Astra software (Version 6.0.2, Wyatt Tech. Corp., Santa Barbara, CA, USA).

The molecular weight (Mw) of AP-SDF was determined by gel chromatography- refractive index–multi-angle laser light scattering system [46 (link)]. The liquid phase system was a U3000 (Thermo Fisher Scientific, Waltham, MA, USA), the differential refractive index detector was an Optilab T-rEX (Wyatt technology, Santa Barbara, CA, USA), and the laser light scattering detector was a DAWN HELEOS Ⅱ (Wyatt technology, Santa Barbara, CA, USA). Gel exclusion columns (Ohpak SB-805 HQ (300 × 8 mm), Ohpak SB-804 HQ (300 × 8 mm) and Ohpak SB-803 HQ (300 × 8 mm)) were used in series. The AP-SDF with a concentration of 1 mg/mL was prepared by mobile phase (0.02% NaN₃, 0.1 M NaNO₃), and the sample size was 100 μL through a 0.45 μm filter. The column temperature was 45 °C and the flow rate was 0.5mL/min. The Mw was calculated by comparing the calibration curves of glucose and dextran standard.

The analysis system for determining molecular weight and its distribution consisted of a high-performance liquid chromatograph (Waters 2695, Milford, MA, USA), a guard column (OHpak SB-G, Shodex, Yokohama, Japan), size exclusion columns (SB-806 HQ and SB-804 HQ column, 7.8 × 300 mm, Shodex, Yokohama, Japan), a multiangle laser light scatterer (DAWN HELEOS Ⅱ, Wyatt Technology, Goleta, CA, USA), and a refractive index detector (RID-20A, Shimadzu, Kyoto, Japan), which was called SEC-MALLS-RI system [24 (link)]. A 0.15 mol/L NaCl solution (containing 0.02% NaN₃) was prepared with ultrapure water as the mobile phase, passed through a 0.22 μm aqueous membrane, degassed by ultrasonication for 30 min, and set aside. Three-milligram samples were dissolved in 1 mL mobile phase and filtered by 0.22 μm hydrophilic membrane before the test. The injection volume and column temperature were 50 μL and 25 °C, respectively. The data would be collected using ASTRA 7.1.2 software for 60 min of each sample with the refractive index increment (dn/dc) of 0.138 mL/g.