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Dna Synthesis Essay

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Chemicals and materials All DNA sequences were synthesized by Integrated DNA Technologies (USA), purified by HPLC and confirmed by mass spectrometry. Sequences are listed in Table 1. Gold(III) chloride trihydrate, trisodium citrate dihydrate, sodium chloride, magnesium chloride, calcium chloride, Trizma pre-set crystal, potassium acetate, acetate acid were bought from Sigma-Aldrich and used as received. SYBR Gold nucleic acid gel stain (10,000 X concentrated in DMSO) was obtained from Invitrogen. Exonuclease III (E. coli) was purchased from New England BioLabs and human apurinic/apyrimidinic endonuclease1 (APE 1) was provided by our collaborator - Dr. Yuan Liu. Table 1. The employed DNA sequences (from 5' to 3'). Thiolated CP Probe (1)*: HST6ACCACATCATCC/iSpC3/TATAACTGAAA …show more content…

Gold(III) chloride solution and sodium citrate solution were freshly prepared with deionized water and filtered through a syringe filter (0.22 µm). Deionized water (45 mL) was added into three-neck flask incubated in the heating mantle with a stirring bar followed by the addition of HAuCl4 solution (5 mL, 10 mM). After the solution was boiling, the sodium citrate solution (5 mL, 38.8 mM) was added quickly. The color of the mixture gradually changed from black to wine red in the first two minutes, indicating the formation of gold nanoparticles. The AuNPs solution was kept boiling for another 10 minutes with a stirring speed of 700 rpm. After cooling down the solution to room temperature, the AuNP solution was filtered through a syringe filter (0.22µm). The concentration of AuNPs was determined by UV-Vis spectrometer (Cary100, …show more content…

The reaction mixtures were challenged with 10 U Exo III for 1 minute or 100 nM APE 1 for 10 minutes at room temperature and then stopped by heat-inactivation at 80 ºC for 10 minutes. Five µL aliquots of the reaction mixtures were subjected to electrophoresis on a 12% denaturing polyacrylamide gel (17 × 15 cm) containing 20 mM Tris-acetate buffer (pH 7.0) with 0.5 mM EDTA at 15 V/cm for 3 hours at room temperature. The gel was stained for 20 minutes with 1× SYBR Gold and imaged using the ChemiDoc MP imaging system

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