Sensitive detection of 5-methylcytosine and quantitation of the 5-methylcytosine/cytosine ratio in DNA by gas chromatography-mass spectrometry using multiple specific ion monitoring
✍ Scribed by Judith Singer; William C. Schnute Jr.; John E. Shively; Charles W. Todd; Arthur D. Riggs
- Publisher
- Elsevier Science
- Year
- 1979
- Tongue
- English
- Weight
- 320 KB
- Volume
- 94
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
A method combining gas chromatography and mass spectrometry (GC-MS) with multiple specific ion monitoring has been developed for the detection of S-methylcytosine and the quantitation of the ratio of methylcytosine to cytosine in DNA. The trimethylsilyl derivatives of cytosine and S-methylcytosine obtained from DNA hydrolysates are separated by isothermal elution on an OV-225 column and detected by specific ion monitoring in a DuPont 321 mass spectrometer. As little as 1.6 pmol of 5-methylcytosine in @x174 DNA can be detected, corresponding to a tenfold improvement in sensitivity over that obtained by conventional techniques. The ratio of 5methylcytosine to cytosine of DNA from @x174, calf thymus, salmon sperm, and several mouse tissues has also been determined. The results agree well with those obtained by other methods.