Investigating rhodamine B-labeled peptoids: Scopes and limitations of its applications

✍ Scribed by Esther Birtalan; Birgit Rudat; Dominik K. Kölmel; Daniel Fritz; Sidonie B. L. Vollrath; Ute Schepers; Stefan Bräse

• Publisher: Wiley (John Wiley & Sons)
• Year: 2011
• Tongue: English
• Weight: 777 KB
• Volume: 96
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.21617

✦ Synopsis

Abstract

The fluorophore rhodamine B is often used in biological assays. It is inexpensive, robust under a variety of reaction conditions, can be covalently linked to bioactive molecules, and has suitable spectral properties in terms of absorption and fluorescence wavelength. Nonetheless, there are some drawbacks: it can readily form a spirolactam compound, which is nonfluorescent, and therefore may not be the dye of choice for all fluorescence microscopy applications. Herein this spirolactam formation was observed by purifying such a labeled peptoid with high performance liquid chromatography (HPLC) and monitored in detail by making a series of analytical HPLC runs over time. Additionally, a small library of eight peptoids with rhodamine B as label was synthesized. Analysis of the absorption properties of these molecules demonstrated that the problem of fluorescence loss can be overcome by coupling secondary amines with rhodamine B. © 2011 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 96: 694–701, 2011.