Peptide Modification Services
Fluorescent, biotin, magnetic-bead, radioactive, and stable-isotope labeling of your peptides.
NHD accepts enquiries for fluorescent or functional peptide-labeling projects. Sequence, attachment site, label, linker, scale, purification target and analytical scope are reviewed before feasibility is confirmed.
Label position can alter binding, folding or signal. The requested attachment chemistry and controls should therefore be defined for the assay rather than assumed from a general service list.
Fluorescent Labels
Common labels that may be considered during feasibility review include:
- Fluorescein family — FITC, 5/6-FAM, and carboxyfluorescein.
- Rhodamine / red dyes — TAMRA, TMR, Rhodamine, and Texas Red.
- Cyanine & near-IR — Cy3, Cy5, Cy5.5, and Cy7 equivalents for deep-tissue imaging.
- Coumarins — AMC/MCA and EDANS for enzyme-substrate work.
Affinity Tags & FRET Pairs
Affinity tags, quenchers and paired reporters require sequence- and assay-specific review.
- Biotin — with or without an aminohexanoic-acid (Ahx) spacer for streptavidin capture.
- FRET / quencher pairs — EDANS/DABCYL, FAM/TAMRA, and Mca/Dnp for protease and conformational assays.
- Click handles — azide/alkyne functionalization for bio-orthogonal conjugation.
Service Specifications
| Parameter | Specification |
|---|---|
| Label classes | Requested label and chemical form reviewed per project |
| Attachment site | Terminus or side-chain position defined in the accepted design |
| Spacers | Linker identity and length confirmed in writing |
| FRET pairs | Donor–acceptor compatibility reviewed for the requested assay |
| Purity | Method and acceptance limit agreed per project |
| QC | Analytical methods and records listed in the quotation |
| Turnaround | Confirmed after sequence and label review |
Frequently Asked Questions
Where should the label go?
It depends on your assay. To preserve a binding motif we place the label away from it (often the opposite terminus) with a short spacer. We advise per project.
Can you make an internally-quenched FRET substrate?
Submit the sequence, cleavage site, donor, quencher and assay conditions. Chemistry, purification and analytical feasibility are confirmed per project.
Do labeled peptides need special handling?
Handling depends on the peptide, label, light sensitivity and formulation. Use the product- or project-specific storage statement and available stability evidence.
Order Labeled Peptides
Send your sequence, desired label(s), and assay context, and we will recommend the attachment chemistry and confirm a quote. Contact our team to start.