1 Technische Universität Braunschweig, Institute for Biochemistry, Biotechnology and Bioinformatics, Spielmannstraße 7, 38106 Braunschweig, Germany.
2 Chair of Bioprocess Engineering, Institute of Biotechnology, Faculty III Process Sciences, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany.
3 University of Gothenburg, Department of Chemistry and Molecular Biology, Division of Organic and Medicinal Chemistry, Kemigåden 4, 412 96 Gothenburg, Sweden.
This report advises against the use of 5-iodoridine or 5-ethynyluridine as alternative assay reagents in the PUB module, primarily due to their lack of an isosbestic point of phosphorolysis under moderately alkaline conditions.