Mass spectrometric analysis of DNA mixtures: instrumental effects responsible for decreased sensitivity with increasing mass.
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has demonstrated great potential to replace gel electrophoresis for DNA sequence analysis. A current limitation in this method is, however, the decreased sensitivity with increasing mass of DNA molecules. In the present study, instrumental effects on the mass analysis of DNA molecules were investigated quantitatively using an equimolar DNA mixture. It is shown that detection efficiency, detector saturation, and ion beam divergence account for the entirety of the observed falloff in signal intensity with increasing mass. Although the present study focused upon the analysis of DNA mixtures, the instrumental effects observed apply equally to other macromolecular mixtures (e.g., proteins, polymers).
Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706-1396, USA.
Xiaoyu
X
Chen
Michael S
MS
Westphall
Lloyd M
LM
Smith
D000465:Algorithms; D000809:Angiotensins / Q000737:chemistry; D001483:Base Sequence; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D007328:Insulin / Q000737:chemistry; D007477:Ions / Q000032:analysis / Q000737:chemistry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009496:Neurotensin / Q000737:chemistry; D009841:Oligonucleotides / Q000032:analysis / Q000737:chemistry; D010047:Ovalbumin / Q000737:chemistry; D011071:Poly T / Q000737:chemistry; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation* / Q000379:methods; D013373:Substance P / Q000737:chemistry; D014159:Transducers
D000809:Angiotensins; D007328:Insulin; D007477:Ions; D009841:Oligonucleotides; D011071:Poly T; D013373:Substance P; D009496:Neurotensin; D010047:Ovalbumin; D004247:DNA