Mass determination of megadalton-DNA electrospray ions using charge detection mass spectrometry
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Charge detection mass spectrometry (CD-MS) has been used to determine the mass of double-stranded, circular DNA and single-stranded, circular DNA in the range of 2500 to 8000 base pairs (1.5–5.0 MDa). Simultaneous measurement of the charge and velocity of an electrostatically accelerated ion allows a mass determination of the ion, with instrument calibration determined independently of samples. Positive ion mass spectra of electrosprayed commercial DNA samples supplied in tris(hydroxymethyl)ethylenediaminetetraacetic acid buffer, diluted in 50 vol. % acetonitrile, were obtained without cleanup of the sample. A CD mass spectrum constructed from 3000 ion measurements takes 10 min to acquire and yields the DNA molecular mass directly (mass resolution = 6). The data collected represent progress toward a more automatable alternative to sizing of DNA by gel electrophoresis. In addition to the mass spectra, CD-MS generates charge versus mass plots, which provide another means to investigate the creation and fate of large electrospray ions.
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- 7.Maniatis, T.; Fritsch, E. F.; Sambrook, J. Molecular Cloning; Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 1982; p 446.Google Scholar
- 22.Bates, A. D.; Maxwell, A. DNA Topology; Oxford University Press: Oxford, 1993; Chap 2, pp 17–44.Google Scholar