tag:blogger.com,1999:blog-32079676.post3614192301747516380..comments2012-01-02T12:17:06.071-08:00Rosie Redfieldhttp://www.blogger.com/profile/06807912674127645263noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-32079676.post-86880672246168380322012-01-02T12:17:06.071-08:002012-01-02T12:17:06.071-08:00Are you worried about the possibility that some amount of arsenate might be bound (non-covalently) to the DNA?<br /><br />If I remember correctly, one of the problems with the Science paper was that they failed to carefully purify the DNA, leaving open the possibility that arsenate was just &#39;stuck&#39; non-specifically to the DNA. While the ethanol precipitation and CsCl gradient are more rigorous than the techniques they used, if the arsenate is &#39;sticky&#39; (poly-saccharide bound?), is it a least plausible that you might observe more arsenate than expected in the DNA peak? <br /><br />I suppose this will all get cleaned up in the mass spec step though --even if there&#39;s arsenate in there, if it is getting integrated into the DNA backbone, you&#39;d expect to see fragments coming out that are consistent with arsenate-carbon compounds, right? Isn&#39;t that how MALDI-TOF works?Dougnoreply@blogger.comtag:blogger.com,1999:blog-32079676.post-80004272517185599482012-01-02T10:33:51.906-08:002012-01-02T10:33:51.906-08:00what&#39;s the difference between green and red? any significance the dna samples running at different positions in the gradient?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32079676.post-87144858243670217122012-01-01T16:35:34.012-08:002012-01-01T16:35:34.012-08:00regarding the soluble contaminants, can you do some kind of precipitation to remove contaminating arsenic (i dont know if arsenic precipitates with ethanol or isopropanol)Dave Bridgeshttp://www.blogger.com/profile/12291507118158076247noreply@blogger.com