Galactose assay kit

Venous blood samples (∼6 mL) were collected into EDTA tubes, stored on ice, and then centrifuged at 4°C and 1,000 g for 15 min. Aliquots of plasma were then stored at −70°C and later analyzed for glucose, lactate, nonesterified fatty acids (NEFA), and glycerol using commercially available kits (Glucose kit, Lactate kit, NEFA kit, Glycerol kit; Randox, London, UK) using an automated photometric clinical chemistry analyzer RX Daytona+ (Randox, London, UK). Plasma galactose concentration was determined using a colorimetric assay (Galactose Assay Kit, Sigma Aldrich, St. Louis, MO) and insulin using an enzyme-linked immunosorbent assay (Invitrogen, Life Technologies, California).

N-Isopropylacrylamide (NIPAM), methacrylic acid (MAA), and 2,2’-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70) were purchased from FUJIFILM Wako Pure Chemical Corporation (Osaka, Japan). NIPAM was used after recrystallization from n-hexane. 2-(Benzylsulfanylthiocarbonylsulfanyl) ethanol (BTSE) [31 (link)] and the Lac-bearing acrylamide derivative (LacAAm) [26 (link)] were synthesized according to previously published methods. β-Galactosidase from Aspergillus oryzae and the galactose assay kit were purchased from Sigma-Aldrich Co., LLC (MO, USA). All other reagents were commercially available and used without further purification.