All Things Chromatography

Thin Layer Chromatography and DNA - the story continues

We first mentioned this discovery here a couple of weeks ago, and just wanted to offer a few more details now that the paper by Skirmantas Kriaucionis and Nathaniel Heintz has been published.

Despite the importance of epigenetic regulation in neurological disorders, little is known about neuronal chromatin. Cerebellar Purkinje neurons have large and euchromatic nuclei, whereas granule cell nuclei are small and have a more typical heterochromatin distribution. While comparing the abundance of 5-methylcytosine in Purkinje and granule cell nuclei, we detected the presence of an unusual DNA nucleotide. Using thin-layer chromatography, high-pressure liquid chromatography, and mass spectrometry, we identified the nucleotide as 5-hydroxymethyl-2'-deoxycytidine (hmdC). hmdC constitutes 0.6% of total nucleotides in Purkinje cells, 0.2% in granule cells, and is not present in cancer cell lines. hmdC is a constituent of nuclear DNA that is highly abundant in the brain, suggesting a role in epigenetic control of neuronal function.

 Click here to read more from Science.

Topics: Nucleotide, HPLC Columns, Thin Layer Chromatography, DNA

Thin Layer Chromatography used in identifying Sixth Nucleotide

From our friends at GenomeWeb.com:

Two researchers from Rockefeller University have identified a new nucleotide...Synthesis of IMP

While evaluating 5-methylcytosine levels in two types of mouse brain cells, the team detected a nucleotide that they could not identify. When they looked more closely at this nucleotide using thin layer chromatography, high pressure liquid chromatography, mass spectrometry, and other approaches, the researchers discovered that they were dealing with 5-hydroxymethylcytosine, a form of methylated cytosine found stably in bacterial viruses.

Their subsequent experiments suggest the nucleotide is enriched in brain cells but apparently absent from several other cell types. Based on these findings, the researchers speculated that 5-hydroxymethylcytosine may contribute to epigenetic regulation, particularly in neurons. 

Click Here to read more from GenomeWeb.com

Topics: Nucleotide, Thin Layer Chromatography, DNA