de.mpg.escidoc.pubman.appbase.FacesBean
English
 
Help Guide Disclaimer Contact us Login
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Extension of the GOOD assay for genotyping single nucleotide polymorphisms by matrix-assisted laser desorption/ionization mass spectrometry

MPS-Authors
http://pubman.mpdl.mpg.de/cone/persons/resource/persons50512

Sauer,  Sascha
Nutrigenomics and Gene Regulation (Sascha Sauer), Independent Junior Research Groups (OWL), Max Planck Institute for Molecular Genetics, Max Planck Society;

Gut,  Ivo G.
Max Planck Society;

Locator
There are no locators available
Fulltext (public)
There are no public fulltexts available
Supplementary Material (public)
There is no public supplementary material available
Citation

Sauer, S., & Gut, I. G. (2003). Extension of the GOOD assay for genotyping single nucleotide polymorphisms by matrix-assisted laser desorption/ionization mass spectrometry. Rapid Communications in Mass Spectrometry, 17(12), 1265-1272. doi:10.1002/rcm.1050.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0010-8B11-2
Abstract
Over the past years several methods using mass spectrometry for high-throughput genotyping of single nucleotide polymorphisms (SNPs) have been developed. Most of these procedures require stringent purification. Only the GOOD assay does not need any sample purification. Here, several new implementations of this assay are presented. The molecular biological procedure of the GOOD assays is based on the principle that the analysis of DNA by matrix-assisted laser desorption/ionization (MALDI) is strongly dependent on the charge state. A 100-fold increase in sensitivity can be achieved if the analyzed DNA product is conditioned by a chemical procedure termed charge-tagging. The GOOD assay starts with a PCR; allele-specific DNA molecules are generated by extension of modified primers. These contain up to three phosphorothioates and optionally a quaternary ammonium charged group with ddNTPs or -S-ddNTPs. Then the unmodified part of the primers is digested by phosphodiesterase II and the negative charges of the phosphorothioates are neutralized by an alkylation reaction resulting in charge-tagged DNA products. Through the use of a novel DNA polymerase for the primer extension, which preferably incorporates ddNTPs over dNTPs, an enzymatic degradation of residual dNTPs from the PCR is not required. Additionally, the unique property of charge-tag technology is demonstrated to detect specifically on the same sample allele-specific DNA products carrying a positive charge-tag in the positive ion mode while products carrying a negative charge-tag are analyzed in the negative ion mode. We also generated zwitterionic allele-specific products that were detectable with high sensitivity in positive ion mode. The findings of this study raise interesting questions about the ionization process of nucleic acids in MALDI. The new variations of the GOOD assay were applied to genotype SNPs of a candidate gene for cardiovascular disease.