The effects of oxygen in positions 4,7 and 5,6 of phenanthroline when this ligand intercalates between guanine-cytosine and adenine-thymine DNA base pairs (GC/CG and AT/TA) have been studied at the M06-2X/6-31+G(d,p) level of calculation. We focused on the changes in the structure, stabilization and energy contributions in the analysis of the interaction. The obtained trends in stabilization are explained by a model including repulsive Pauli (ΔE) contributions, and attractive dispersion (ΔE), orbital (ΔE) and electrostatic (ΔE) contributions to energy. When no solvation is considered, the intrinsic ΔE contribution results are crucial for the stabilization of the system. However, the inclusion of the solvation energy ΔE can reverse the final stability trend of the systems becoming, thus, the driving force of the process. Therefore, the solvent will have a relevant influence in the potential cytotoxicity of the intercalation drugs.

Methods for the detection of m6A by RNA-Seq technologies are increasingly sought after. We here present NOseq, a method to detect m6A residues in defined amplicons by virtue of their resistance to chemical deamination, effected by nitrous acid. Partial deamination in NOseq affects all exocyclic amino groups present in nucleobases and thus also changes sequence information. The method uses a mapping algorithm specifically adapted to the sequence degeneration caused by deamination events. Thus, m6A sites with partial modification levels of ∼50% were detected in defined amplicons, and this threshold can be lowered to ∼10% by combination with m6A immunoprecipitation. NOseq faithfully detected known m6A sites in human rRNA, and the long non-coding RNA MALAT1, and positively validated several m6A candidate sites, drawn from miCLIP data with an m6A antibody, in the transcriptome of Drosophila melanogaster. Conceptually related to bisulfite sequencing, NOseq presents a novel amplicon-based sequencing approach for the validation of m6A sites in defined sequences.

Accurate quantification of the copy numbers of noncoding RNA has recently emerged as an urgent problem, with impact on fields such as RNA modification research, tissue differentiation, and others. Herein, we present a hybridization‐based approach that uses microscale thermophoresis (MST) as a very fast and highly precise readout to quantify, for example, single tRNA species with a turnaround time of about one hour. We developed MST to quantify the effect of tRNA toxins and of heat stress and RNA modification on single tRNA species. A comparative analysis also revealed significant differences to RNA‐Seq‐based quantification approaches, strongly suggesting a bias due to tRNA modifications in the latter. Further applications include the quantification of rRNA as well as of polyA levels in cellular RNA.