Mass-spectrometry DNA sequencing.
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been explored widely for DNA sequencing. Compared to gel electrophoresis based sequencing systems, mass spectrometry produces very high resolution of sequencing fragments, rapid separation on microsecond time scales, and completely eliminates compressions associated with gel-based systems. While most of the research efforts have focused on using mass spectrometers to analyze the DNA products from Sanger sequencing or enzymatic digestion reactions, the read lengths attainable are currently insufficient for large-scale de novo sequencing. The advantage of mass-spectrometry sequencing is that one can unambiguously identify frameshift mutations and heterozygous mutations making it an ideal choice for resequencing projects. In these applications, DNA sequencing fragments that are the same length but with different base compositions are generated, which are challenging to consistently distinguish in gel-based sequencing systems. In contrast, MALDI-TOF MS produces mass spectra of these DNA sequencing fragments with nearly digital resolution, allowing accurate determination of the mixed bases. For these reasons mass spectrometry based sequencing has mainly been focused on the detection of frameshift mutations and single nucleotide polymorphisms (SNPs). More recently, assays have been developed to indirectly sequence DNA by first converting it into RNA. These assays take advantage of the increased resolution and detection ability of MALDI-TOF MS for RNA.
Edwards
John R
JR
Columbia Genome Center, Columbia University College of Physicians and Surgeons, Room 405A, Russ Berrie Medical Science Pavilion, New York, NY 10032, USA.
Ruparel
Hameer
H
Ju
Jingyue
J
D001483:Base Sequence; D016368:Frameshift Mutation; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization