Fourteen ammonium salts have been investigated as co-matrices for negative-ion matrix-assisted laser desorption/ionization (MALDI) analysis of a number of synthetic oligonucleotides in three different matrix systems, including 2,5-dihydroxybenzoic acid, 2-amino-5-nitropyridine (ANP) and 3-hydroxypic
Use of Ammonium Halides as Co-matrices for Matrix-assisted Laser Desorption/Ionization Studies of Oligonucleotides
โ Scribed by Sau-wan Cheng; T.-W. Dominic Chan
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 322 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0951-4198
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โฆ Synopsis
Four ammonium salts, NH,F, NH,Cl, NH4Br and NHJ were tested as co-matrices for the matrix-assisted laser desorptiodionization (MALDI) analysis of a number of DNA homopolymers, including phosphorylated a("),, d(A),, d(C), and non-phosphorylated d(G),, using 2-amino-S-nitropyridine (ANP) matrix. In the present study, all the ammonium halides displayed significant enhancement effects on the signal intensities of the intact molecular ions of the DNA homopolymers. Among the halides used, N&F was found to exhibit the greatest enhancement effects. By comparison with results obtained using the corresponding isomorphous potassium halides as comatrices, it is postulated that both the cationic and anionic portions of the co-matrix molecule play important roles in the desorption/ionlzation of the oligonucleotides under typical MALDI conditions. It was also demonstrated that the ANP matrix exhibits a strong inhibitory effect on the formation of alkali-metal adducts in oligonucleotide analysis.
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