Analytical Sciences

Matrix Effect on the Analysis of Oligonucleotides by Using a Mass Spectrometer with a Sonic Spray Ionization Source

Min HUANG,*  Atsumu HIRABAYASHI,** Akihiko OKUMURA,** and Yukiko HIRABAYASHI**

*Life Science Group, Hitachi Ltd., 1-3-1, Minamidai, Kawagoe, Saitama 350-1165, Japan
**Central Research Laboratory, Hitachi Ltd., 1-280, Higasi-Koigakubo, Kokubunji, Tokyo 185-8601, Japan

Matrix or impurities remaining in a DNA sample solution after various sample treatment procedures may influence a subsequent DNA analysis. In this work, several matrices were investigated concerning their effects on the analysis of oligonucleotide by using an ion-trap mass spectrometer equipped with a sonic spray ionization source. Inorganic salts of sodium chloride and magnesium chloride depressed the signal intensity by about 50% when the content of the salts was about 10 uM. dNTPs and Taq showed more severe depression on the oligonucleotide. However, Tris, or (hydroxymethyl)aminomethane, intensified the signal intensity, if its content was within an appropriate range. When the content of Tris was about 500 uM, the signal intensity was enhanced by factors of 3 and 5 for the 6-mer and the 20-mer oligonucleotides, respectively. With the existence of Tris, matrix effects from the inorganic salts, dNTPs and Taq were reduced.

J-STAGE: View this article in J-STAGE