A mixed matrix of 3-hydroxypicolinic acid and pyrazinecarboxylic acid for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of oligodeoxynucleotides.
A mixed matrix of 3-hydroxypicolinic acid (3-HPA) and pyrazinecarboxylic acid (PCA) was used for analysis of a variety of synthetic oligodeoxynucleotides ranging in length from 8-108-mers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The experimental results showed that DNA segments with masses in the range from 5000 to 10,500 Da can be analyzed with high resolution (isotopic peaks resolved) when 3-HPA/PCA was prepared by mixing saturated 3-HPA solution and saturated PCA solution (in 50% of a 0.5 mol/L solution of diammonium hydrogen citrate plus 50% acetonitrile) at the volume ratio of 4:1. Each component of a mixture of d(A)1-10 gave a well-resolved peak. Moreover, when 3-HPA/PCA was used to analyze two mixtures, one containing two 23-mer DNA segments with a 9 Da difference (A and T) and the other with a 7 Da difference (AA and TG), the two 23-mer ion peaks were well separated from each other and an isotopically resolved spectrum of each component was recorded. Under the identical experimental conditions, the sample-to-sample reproducibility, resolution, signal-to-noise ratio and the tolerance to metal salts, with 3-HPA/PCA, were superior to those observed using 3-HPA alone for analysis of DNA segments.
Zhou
Lihua
L
Instrumental Analysis & Research Center, Sun Yat-Sen University, Guangzhou 510275, Guangdong, P.R. China.
Deng
Huimin
H
Deng
Qinying
Q
Zhao
Shankai
S
D001483:Base Sequence; D004247:DNA / Q000032:analysis / Q000235:genetics; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000032:analysis* / Q000235:genetics; D010848:Picolinic Acids; D011718:Pyrazinamide / Q000031:analogs & derivatives*; D015203:Reproducibility of Results; D012996:Solutions; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation*
D009838:Oligodeoxyribonucleotides; D010848:Picolinic Acids; D012996:Solutions; D011718:Pyrazinamide; C005296:pyrazinoic acid; C049246:3-hydroxypicolinic acid; D004247:DNA