Hi Bernhard, We know this problem since the very early days of the His-tag and have been using high purity imidazole from Merck since then with success, which essentially shows no absorption at 280 nm. If you like I can enquire the current order number in my lab.
Cheers, ASk Am 21.08.2013 um 16:33 schrieb Bernhard Rupp: > Hi Fellows, > > could someone please point me towards the source of a known high purity > imidazole > with low absorbance at 280 nm? I am facing the problem of detecting a low > absorption protein > in high imidazole background after IMAC gradient elution. In the UV spectra > of the > 2 imidazoles I checked there is some contaminant that absorbs at 280… > > Thx, BR > > ---------------------------------------------------------------------------------------- > Bernhard Rupp > Marie Curie Incoming International Fellow > Innsbruck Medical University > Schöpfstrasse 41 > A 6020 Innsbruck – Austria > +43 (676) 571-0536 > [email protected] > ---------------------------------------------------------------------------------------- > Dept. of Forensic Crystallography > k.-k. Hofkristallamt > Vista, CA 92084 > 001 (925) 209-7429 > [email protected] > [email protected] > http://www.ruppweb.org/ > ----------------------------------------------------------------------- Prof. Dr. Arne Skerra Lehrstuhl f. Biologische Chemie | Technische Universitaet Muenchen Emil-Erlenmeyer-Forum 5 | 85350 Freising-Weihenstephan | Germany Phone: +49 (0)8161 71-4351 | Fax: -4352 http://www.wzw.tum.de/bc | eMail: [email protected]
