Formamide deionized

Formamide deionized by stirring for 30 mm with 10% (w/v) of a mixed-bed ion exchange resm (e.g, Bio-Rad AG 501-X8,20-50 mesh, Bio-Rad, Hercules, CA), filtering twice through Whatman (Clifton, NJ) no 1 paper and storing smgle-use aliquots at -80°C... 

Formamide, deionized by stirring Dowex XG8 resin beads (5 g/100 mL formamide) for 1 h, filtered through Whatman No 1 paper, and stored in aliquots at-20°C. 

Formamide (specific conductance 2 x 10 ohnr cnr ) of low water content was dried by passage through a column of 3A molecular sieves, then deionized by treatment with a mixed-bed ion-exchange resin loaded with H" " and HCONH" ions (using sodium formamide in formamide)[Notley and Spiro J Chem Soc (B) 362 1966. ... 

Materials. Reagent grade solvents, dimethyl formamide (DMF), dimethyl acetamide (DMAC), dimethyl sulfoxide (DMSO) and methanol were purchased from Baker, stored over molecular sieves once opened, and used without further purification. Aminoethane thiosulfuric acid (AETSA) purchased from Kodak, and Taurine, purchased from Alfa were purified by recrystallization. Each was thrice recrystallized from hot, deionized water. The crystalline precipitate was dried (48 hours at 40 °C) in-vacuo and subsequently stored in a desiccator. Benzophenone (BP) was purchased from Aldrich Chemical Company. QUANTACURE BTC (BTC), (4-benzolybenzyl) trimethylammonium chloride, was used as supplied by Aceto, Inc., Flushing, New York. Phenyl glycidyl ether (PGE) was purchased from MCB, distilled in-vacuo. and stored at -15 °C. Epon 828 was used as supplied bv Shell Chemical Company. The epoxy equivalent weight (EEW) for Epon 828 determined by an appropriate titration, was found to be 187.7. 

Hybridization solntion (Boehringer Mannheim) Deionized formamide 20X SSC lOOX Denhardt solntion 10 mg/mL Salmon sperm DNA 10% SDS. 

Add 2 ng/pL digoxigenin-labeled oligo probe into the following hybridization solution 50% deionized formamide, 10 mL 20X SSC, lOX (final concentration) lOOX Denhardt solution, 1 mg/mL (final concentration) 10 mg/mL salmon sperm DNA, 1% (final concentration) 10% SDS. 

The photocurrent density of nanotube array samples fabricated in an electrolyte of 1.2 g of NH4F in a solution of 5 ml deionized water + 95 ml formamide at 35 V is shown in Fig. 5.46(a). The resulting nanotube array samples were 30 pm in length, with an outer diameter of 205 nm. The samples were annealed at 525°C and 580°C for 1 hour in oxygen prior to measurement. The 580°C annealed sample had an open circuit voltage Voc of -0.925 V (vs. Ag/AgCl) the 525°C annealed sample had an open circuit voltage... 

A working solution Immediately before using, Soln. A is diluted 1 20 with Soln. B. The working dilution can be used only once. B 50% formamide (v/v) in deionized water. 

Hybridization buffer 50% deionized formamide, 10% dextran sulfate, 250 pg/mL sheared herring sperm DNA, 0.01% polyvinyl pyrrolidone and 0.1% sodium dode-cyl sulfate in 2X SET buffer... 

Deionized formamide- Mix 5.0 g mixed-bed ion-exchange resin (Bio-Rad [Hercules, CA] AG501-x8,20-50 mesh) with 50 mL formamide. Stir for 45 mm, and filter with Whatman s filter paper. Store in aliquots at-20°C... 

Each section is covered with 100 xl of freshly prepared hybridization solution Deionized formamide (65%)... 

To terminate the reaction the capillary contents are ejected into 5yu.l formamide dye mix (99% deionized formamide containing 10 mM EDTA, 0.2 mM NaOH, 0.1% xylene cyanol FF dye). After denaturation at 100°C for 30 s the samples are applied directly into gel wells and electrophoresis carried out by the usual method (Section 3.1.2.). Seif et al. (1980) give a recommended order of loading ... 

Deionize 100 ml formamide with 5g Amberlite MB1 resin. Remove resin by filtration. Add 0.03 g xylene cyanol FF, 0.03 g bromophenoi blue and Na2EDTA to 20 mM. Store at room temperature. 

Prehybridization/hybridization buffer 50% deionized formamide, 5 X SSC (standard saline citrate), 8 X Denhardt s solution, 50 mM sodium phosphate buffer (pH 6.5), 0.5% sodium dodecyl sulfate (SDS), 250 fig/ml denatured herring testes DNA, and 500 ng/ml yeast RNA (for the composition of SSC buffer and Denhardt s solution, see, e.g., Ausubel et al.13)... 

Hybridization Procedure. Formamide is deionized by adding 1 g of mixed bed ion-exchange resin (e.g., AG 501-X8, Bio Rad, Hercules, CA) to 10 ml of formamide, which is stirred on a magnetic stirrer for at least 1 hr and then filtered twice through filter paper. Store at —20°. Prehybridize filters in the above buffer for 4-8 hr at 45°, replace the solution with fresh... 

Deionized formamide Mix 5 g of mixed bed ion-exchange resin (Bio-Rad AG501-x8, 20-50 mesh) with 50 mL of formamide. 

Deionized formamide Add 5 g of monobed resin per 50 mL of analar formamide and stir for 45 min at room temperature. Filter through Whatman No. 1 paper prior to use. 

Denionized formamide/dextran sulfate Add 10% w/v of dextran sulfate (DS) to deionized formamide and allow it to dissolve with constant... 

Use deionized formamide in the hybridization solution and ensure that the dextran sulfate is fully dissolved prior to aliquoting and storage at -20°C. Deterioration of this solution eventually leads to increased background, so replace this stock every three months. 

Deionized formamide Molecular biology grade formamide (Fluka) is mixed with 150 g/L of AG-X-100 mixed bed resin (Bio-Rad, Hercules, CA) for 1 h at room temperature (covered, in a chemical hood). The deionized formamide is filtered (with gentle vacuum) over Whatman filter paper twice (one filtering will not remove all the resin). Deionized formamide is stored in 50-mL aliquots in screw-capped tubes at -70°C and can be kept for up to 1 yr. 

Loading dye solution 98% deionized formamide, 10 mMEDTA, 0.025% xylene cyanol, 0.025% bromophenol blue. 

Note The pH of the formaldehyde solution (37% or 12.3 M) should be at least 4.0 and the formamide solution should not be yellowish otherwise deionize, e.g., by mixing with Dowex XG8 and filtration through Whatman filters or over an AG-501-X8 column (Bio-Rad). 

Dissolve vacuum-dried RNA in sample buffer (10 pg/50 p.1 1 x MOPS buffer, 5 mM NaOAc and 1 mM EDTA, pH 6-7, 6.5% formaldehyde, 50% deionized formamide) and add then 10 pi of loading buffer (1 mM EDTA, pH 8.0, 0.25% bromophenol blue, 0.25% xylene cyanol, 50% glycerol) and 2 pi of ethidium bromide (0.5 pg/pl). Heat the sample for 15 min at 55°C, quench on ice and load on formamide gel (Table 9.7 1.2% agarose, 1.1% formaldehyde). Run electrophoresis at 5 V/cm with recirculation of lx MOPS buffer. In this procedure, only sample and loading buffer and MOPS electrophoresis buffer are DEPC-treated. Separation of RNA can be followed by the separation of the 18S and 28S rRNA bands (MOPS buffer as in Table 9.7 B). 

---