A new technique can simultaneously sequence DNA and pinpoint some of the chemical modifications that turn genes on or off, according to a report published 9 May in Nature Methods.In particular, the technique reveals methyl groups bound to DNA bases. DNA methylation — one of several types of 'epigenetic' changes — allows organisms to express genes at various times, and in different tissues, without changing the underlying DNA code.Read more at...SFARI, May 2010.