Indiana Section of the Society for Applied SpectroscopyIndiana Section of the Society for Applied Spectroscopy
1999-2000 Seminar Abstracts
RAPID
DNA SEQUENCING VIA ELECTROSPRAY AND
ION/ION CHEMISTRY IN A QUADRUPOLE ION TRAP
Scott A. McLuckey
Department
of Chemistry, Purdue University, West Lafayette, Indiana 47907
My
colleagues at Oak Ridge National Laboratory and my group at Purdue are pursuing
a methodology for high speed DNA sequencing based on electrospray ionization
mass spectrometry employing gas-phase ion/ion chemistry in a quadrupole ion
trap. DNA sequencing via mass
spectrometry has been pursued by a number of groups in recent years due to its
promise for the obviation of time-consuming electrophoresis-based separations
required with established sequencing strategies.
By far, most effort has been directed toward matrix-assisted laser
desorption ionization (MALDI) combined with time-of-flight mass spectrometry. While a MALDI-based approach may yet fulfill its promise,
limitations encountered in ionizing relatively large DNA oligomers have proved
to be difficult to overcome. In
contrast, ionization of large DNA oligomers is not a limitation for electrospray
ionization. However, electrospray-based
approaches for high speed DNA sequencing have not been extensively pursued due
to spectral congestion associated with the multiple charging phenomenon that is
characteristic of electrospray. The
formation of multiple charge states from a single oligomer severely limits the
mixture complexity amenable to direct analysis via electrospray.
For this reason, electrospray usually follows a separation method, such
as liquid chromatography or capillary electrophoresis, when applied to mixtures.
We have recently shown that gas-phase ion/ion chemistry involving
oppositely charged ions within a quadrupole ion trap greatly expands the mixture
analysis capability of electrospray. In
this work, the idea is to subject Sanger mixtures to electrospray and ion/ion
chemistry as a core element in a strategy for high speed DNA sequencing.
This talk describes the methodology and progress to date.
Contact Indiana Section of the Society for Applied Spectroscopy