Ethylenediaminetetraacetic acid edta

CM-dextran sodium salt (CMD-Na), phosphate-buffered saline (PBS), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), N-hydroxysulfosuccinimide (NHS), ethanolamine, potassium chloride (KCl), potassium ferricyanide (Fe(CN)₆³⁻), hydrogen peroxide (H₂O₂), diethyl pyrocarbonate (DEPC), and 3,3′,5,5′-tetramethylbenzidine (TMB) were purchased from Sigma-Aldrich (Sigma-Aldrich St. Louis, MO, USA). Anti-fluorescein horseradish peroxidase (HRP) is a 40,000 dalton protein supplied by Abcam (Cambridge, UK). MES free acid monohydrate, hydroxymethyl-aminomethane (Tris), and ethylenediaminetetraacetic acid (EDTA) were purchased from Amresco (Amresco Inc., Solon, OH, USA). Core streptavidin was from BiVision (Bioptics, Tucson, AZ, USA). Sodium chloride (NaCl) was from Promega Corporation (Madison, WI, USA). The biotinylated ssDNA probe (bioreceptor probe) (5′-CAGACAGTGTTA-3′-(CH2)₆-biotin), fluorescein (FITC) ssDNA probe (detector probe) (FITC-(CH2)₆-5′-CCATCTTTAC-3′), and artificial mimic targeting sequence (5′-UAA CAC UGU CUG GUA AAG AUG G-3′) were designed by us and made by Genomics (Taipei, Taiwan). Screen-printed carbon electrodes (SPCEs) were purchased from Zensor R&D (Taichung, Taiwan).

Citric acid monohydrate (C₆H₈O₇·H₂O) as carbon source and Polyethylenimine (PEI1800, branched average molecular weight 1800) as nitrogen source were obtained from OCI Company (Seoul, Korea) and Alfa Aesar (Haverhill, MA, USA), respectively. All metal ions were prepared using their nitrate, sulfate, or chloride salts that were purchased from Sigma-Aldrich (Seoul, Korea). Ethylenediaminetetraacetic acid (EDTA) was received from Amresco (Solon, OH, USA). Deionized (DI) water at 18.2 MΩ cm was purified using a Milli-Q system (Purescience, Seongnam, Korea). All reagents were of analytical grade and were used for the experiment without further purification.

Dithiothreitol (DTT), nitroblue tetrazolium (NBT), H₂O₂, titanium dioxide, dichloromethane, pyridine, N,O-bis(trimethylsilyl) trifluoroacetamide, trimethylsilyl chloride, sodium azide, thiobarbituric acid (TBA), methionine, catalase, peroxidase, cholesterol, maltose, octadecane, phenol, palmitic acid, sorbitol, ammonia and potassium phosphate buffer were purchased from Sigma-Aldrich (Saint Louis, MO, USA). Tetracosane and 4-aminoantipyrine were purchased from Fluka (Bucharest, Romania). Sulfuric acid was purchased from Fisher Chemical (New Hampshire, EUA). TrichloroAcetic acid (TCA) was purchased from BIOCHEM Chemopharma (Cosne-Cours-sur-Loire, France). Guaiacol and polyvinylpyrrolidone (PVP) were purchased from Acrós Organics. Triton-X and ascorbic acid were purchased from Panreac. Acetic acid, ethylenediaminetetraAcetic acid (EDTA) and phenylmethylsulfonyl fluoride (PMSF) were purchased from VWR (Pennsylvania, EUA). Riboflavin, n-hexane p.a., methanol p.a., sodium carbonate (Na₂CO₃), dimethyl sulfoxide (DMSO), potassium sulfate and quercetin were purchased from Merck (Darmstadt, Germany). Luteolin and oleuropein were purchased from Extrasynthese (Genay, France).

The analytical standards 2-thiouracil (TU), 6-dimethyl-thiouracil, 6-ethyl-thiouracil, 6-methyl-2-thiouracil, 6-propyl-2-thiouracil, and 6-phenyl-thiouracil were purchased from Sigma-Aldrich (St. Louis, MO, USA), whereas the deuterated internal standard 6-propyl-2-thiouracil-d₅ (PTU-d₅) was from Toronto Research Chemicals (Toronto, Canada). Stock (1 mg mL^-1) and working solutions (1 and 0.1 ng μL^-1) were prepared in methanol and stored in dark glass bottles at -20°C.
Reagents were of analytical grade when used for extraction purposes and of LC-MS grade for UHPLC-MS applications. They were respectively purchased from VWR International (Merck, Darmstadt, Germany) and Fisher Scientific (Loughborough, UK). Ethylenediaminetetraacetic acid (EDTA) was from VWR International (Merck, Darmstadt, Germany) and hydrogen chloride from Sigma-Aldrich (St. Louis, MO, USA). Phosphate buffer was adjusted to a pH of 7 and saturated with 1% of DL-dithiothreitol (DTT) (Sigma-Aldrich, St. Louis, MO, USA). Ultrapure water (0.055 μS cm^-1) was obtained by means of a purified-water system (Sartorius AG, Göttingen, Germany).

Yeast extract and curcumin were obtained from Acros Organics (Geel, Belgium). Tryptic soy agar and gold(III) chloride trihydrate were acquired from MP Biomedicals (Santa Ana, CA). Ampicillin, isopropyl β-D-1-thiogalactopyranoside (IPTG), imidazole, sodium monobasic phosphate, sodium dibasic phosphate, sodium dodecyl sulfate, sodium hydroxide, sodium chloride, sucrose, tris-hydrochloride, tryptone, PFU high fidelity, DpnI, ACS grade methanol and urea were obtained from Fisher Scientific (Pittsburgh, PA). 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), magnesium sulfate, nickel chloride, sodium borohydride were purchased from Sigma Aldrich (St. Louis, MO). Tricine was purchased from Alfa Aesar (Ward Hill, MA). Glacial acetic acid and Factor Xa cleavage kit were purchased from EMD Millipore (Rockland, MA). Ethyl acetate was purchased from Pharmco-AAPER (Brookfield, CT). Ethylenediaminetetraacetic acid (EDTA) and hydrochloric acid were acquired from VWR (Radnor, PA). HPLC grade methanol was obtained from Ricca Chemical Company (Arlington, TX). Sephadex™ G-25 medium beads were purchased from Amersham Pharmacia Biotech AB (Piscataway, NJ). Columns were purchased from Bio-Rad (Hercules, CA).