Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Page 1 of 2 Ammonium Acetate BioChemica Synonym Essigsäureammoniumsalz state of matter Solid Solubility (20°C) 1480 g/L (H2O) Melting point 114°C Formula CH3COONH4 M 77.08 g/mol CAS-No.: 631-61-8 HS-No.: 29152900 EC-No.: 211-162-9 Storage: RT LGK: 10 - 13 Disposal: 14 WGK: 1 Specification Assay (titr.) min. 98 % pH (5 %; H2O) 6.5 - 7.3 (25°C) Heavy metals (as Pb) max. 0.001 % Insoluble matter passes test Water max. 2.5 % Chloride max. 0.002 % Sulfate max. 0.005 % A (1 cm/1 M in H2O) 260 nm max. 0.03 280 nm max. 0.02 A3674 Page 2 of 2 Ammonium Acetate BioChemica A3674 Literature (1) Okayama, H. & Berg, P. (1982) Mol. Cell. Biol. 2, 161-170 High-efficiency cloning of full-length cDNA. (2) Wallace, D.M. (1987) Methods Enzymol. 152, 41-48 Precipitation of nucleic acids. (3) Ausubel, F.A., Brent, R., Kingston, R.E., Moore, D.D., Seidman, J.G., Smith, J.A. & Struhl, K. (eds.) (1995) Current Protocols in Molecular Biology, Pages 15.3.1-4 (Suppl. 17) Greene Publishing & Wiley-Interscience, New York. (4) Saporito-Irwin, S.M. et al. (1997) BioTechniques 23, 424-427 Protocol for the preparation of plasmid DNA, suitable for the transfection of mammalian cells. Comment All references describe methods for the precipitation of nucleic acids using ammonium acetate (NH4OAc), instead of the commonly used sodium acetate. Stock solutions are made of 10 M (ref. 3; 770 g/L, filtered) or 7.5 M ammonium acetate (4). Precipitation of DNA: Make the DNA-containing sample 2.5 M ammonium acetate by adding 0.5 volume 7.5 M ammonium acetate stock solution. Mix well and add 2.5 to 3 volumes (DNA-sample + ammonium acetate) ethanol (example: 1 ml DNA-containing sample + 0.5 ml ammonium acetate; mix well; add 3.75 to 4.5 ml ethanol). Mix well and incubate for 10 minutes in a dry ice bath or a -70°C freezer. Nucleotides and oligonucleotides will not be precipitated, which will coprecipitate with the DNA, if sodium acetate is employed. Two consecutive precipitations will remove 99 % of the nucleotides and result in a DNA recovery of more than 90 %. The quality of the DNA resulting from this protocol is sufficient for the transfection of mammalian cells. The preparation is much cheeper than the purification with cesium chloride (3). Caution! Ammonium acetate shall not be used, if the purified DNA has to be phosphorylated, because ammonium ions will inhibit the kinase. Precipitation of RNA: Add to a 10 ml aqueous RNA-containing sample 0.1 volume 3 M NH4OAc (pH 5.5; 1 ml; final conc. 0.3 M) and mix. Then add 27.5 ml (2.5 volumes) ethanol and mix. Incubate the sample for 10 minutes at -70°C in a dry ice bath or a freezer. Ammonium acetate can be a substitute for potassium acetate, when the RNA is used in a cell-free translation system.