Related Experiment Video
Updated: Aug 14, 2026

Phthalic Acid Ester-Binding DNA Aptamer Selection, Characterization, and Application to an Electrochemical Aptasensor
Published on: March 21, 2018
Location and base selectivity on fragmentation of brominated oligodeoxynucleotides
Corinne Buré1, Bertrand Castaing, Catherine Lange
1Centre de Biophysique Moléculaire, CNRS UPR 4301, University of Orléans and INSERM, rue Charles Sadron, 45071 Orléans Cedex 02, France. bure@cnrs-orleans.fr
Abstract:
Bromine-modified oligodeoxynucleotides (ODNs) were fragmented in the electrospray source to study the influence of brominated bases on fragmentation. Several 13-mer ODNs containing a brominated pyrimidine base, BrdU (5-bromodeoxyuridine) or BrdC (5-bromodeoxycytidine), were analyzed. Low cone voltage fragmentation yields a loss of the brominated base with a preferential loss for the brominated base closer to the 5'-end (2-position > 4-position > 12-position) as well as a preferential loss of BrdU over BrdC. Higher cone voltage produces backbone fragmentation with complementary a(n)-base and w(m) ions close to the brominated base. On the basis of these observations, we located the brominated base in the sequence for all of the ODNs studied.
Related Concept Videos
Long-patch Base Excision Repair
Regioselectivity of Electrophilic Additions-Peroxide Effect
Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
Mass Spectrometry: Alkyl Halide Fragmentation
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Maxam-Gilbert Sequencing
Challenges of the Maxam-Gilbert Method
The...

