Hi Alex, In addition to Mirella's suggestion I would like to make an addition which might be specifically useful for you. Since your peptide has biotin tag, You may use HABA dye assay for the exact quatifiation of biotin (and thus biotinylated peptide). As far I recall, Thermo scientific provide a kit for this assay. The assay is simple and gives accurate results.
Best !!! Debasish CSIR- Senior Research Fellow (PhD Scholar) C/o: Dr. Akash Ranjan Computational and Functional Genomics Group Centre for DNA Fingerprinting and Diagnostics Hyderabad, INDIA Email(s): dkgh...@cdfd.org.in, dgho...@gmail.com Telephone: 0091-9088334375 (M), 0091-40-24749396 (Lab) Lab URL: http://www.cdfd.org.in/labpages/computational_functional_genomics.html ----- Original Message ----- From: Alex Lee <alexlee198...@gmail.com> To: CCP4BB@JISCMAIL.AC.UK Sent: Mon, 06 Feb 2017 03:02:07 +0530 (IST) Subject: [ccp4bb] How to determine the concentration of biotinylated peptide? Dear All, Sorry for the off-topic question, I'd like to do Biacore SPR assay with N-terminal biotinylated peptide as ligand (to Biacore SA chip) and my protein as analyte. I have a question of how to determine the concentration of biotinylated peptide (synthetic peptide), if the peptide has no Tyr and no Trp residue, I guess amino acid analysis may not work because the N-terminal of the peptide is biotinylated. I'd appreciate if anyone share his/her experience on this.