title: Hoechst likes to play hide and seek...use it with caution!
abstract: We describe an unexpected feature of the dye Hoechst 33342 that may lead to misinterpretation of fluorescence assay results. When dissolved in aqueous solvent, Hoechst 33342 massively adsorbs on the polytetrafluoroethylene (PTFE)-coated stirrer and on the quartz cuvette. The interaction between the dye and the PTFE is stronger than that between the dye and the quartz. We show that Hoechst 33342 adsorption on quartz is due to its amphiphilic properties, as it depends on the buffer ionic strength and on pH. We suggest a procedure to detect and remove any residual Hoechst 33342.
authors.affiliation: Laboratoire de Cristallographie et RMN Biologiques (CNRS UMR 8015), Faculté de Pharmacie, Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France.
authors.forename: Alice
authors.initials: A
authors.lastname: Verchère
authors.forename: Isabelle
authors.initials: I
authors.lastname: Broutin
authors.forename: Martin
authors.initials: M
authors.lastname: Picard
mesh_terms: D000327:Adsorption; D016477:Artifacts; D001562:Benzimidazoles / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D012107:Research Design; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D001562:Benzimidazoles; D004396:Coloring Agents; D012997:Solvents; C017807:bisbenzimide ethoxide trihydrochloride
keywords: Fluorescent substrate; Hydrophobic interaction; Membrane protein