技术文章

Fluorescent-Labeled Peptides

Fluorescent-labeled peptides are a class of bioactive peptides covalently conjugated with fluorescent moieties, enabling molecular-level visualization with high sensitivity, safety, and cost-effectiveness. The principle relies on the fact that fluorophores contain conjugated double-bond systems that, upon excitation by ultraviolet or violet-blue light, return from an excited state to the ground state while releasing photons, thereby generating detectable fluorescence signals.

1. Key Features and Advantages

High sensitivity: Capable of detecting molecules at very low concentrations for precise imaging.

Non-radioactive and safe: No radioactive contamination, ensuring safe experimental operations.

Cost-effective: More economical compared with radioactive labeling or advanced imaging technologies.


2.Selection of Fluorophores

In vitro studies: Fluorophores with emission wavelengths of 400–600 nm (e.g., AMC, FITC, TAMRA) are widely applied in cell-based or protein-based assays.

In vivo imaging: Fluorophores with emission wavelengths of 650–900 nm (e.g., ICG, Cy5.5, Nile Blue) provide strong tissue penetration and low background interference.


3. Applications of Fluorescent-Labeled Peptides

3.1 Peptide Synthesis and Labeling

Fluorophores are typically conjugated to the N-terminus or C-terminus of peptides via covalent bonds to preserve biological activity. For long-chain peptides, FRET (Förster Resonance Energy Transfer) donor–acceptor pairs can be introduced within the sequence to investigate protein–protein interactions.

3.2 Application of FRET Technology

FRET technology enables the study of intermolecular interactions through non-radiative energy transfer between donor and acceptor fluorophores. FRET efficiency is inversely proportional to the sixth power of the donor–acceptor distance, allowing precise monitoring of protein–protein interactions, enzymatic activity, and molecular dynamics.

3.3 In vitro and In vivo Imaging

In vitro imaging: Confocal and fluorescence microscopy with labeled peptides allows efficient investigation of intracellular molecular targets and biological processes.

In vivo imaging: Fluorescent-labeled peptides enable real-time imaging in living organisms, applied in angiography, tumor imaging, and other biomedical fields, supporting precision medicine and personalized therapeutic strategies.


4.Common Fluorescent Modifications for Peptides

Name

Excitation (nm)

Emission (nm)

Emission Color

7-Methoxycoumarin-4-acetic acid

328

393

Blue

FITC-Ahx

494

521

Green

FAM

495

520

Green

Cy3

555

570

Yellow

5-Carboxytetramethylrhodamine (TMR)

542

568

Orange

Cy5

646

662

Red

Cy5.5

673

707

Near-infrared

Cy7

750

773

Near-infrared


5.Representative FRET Pairs

Donor

Ex (nm)

Em (nm)

Acceptor

Ex (nm)

Em (nm)

Cy2

490

510

Cy3

555

570

FITC

494

521

TRITC

557

576

FAM

495

520

Cy3

555

570

FAM

495

520

Texas Red

589

615

FAM

495

520

Cy5

646

662

Cy3

555

570

Cy5

646

662

EDANS

335

493

DABCYL

453

-

Glu(EDANS)-NH2

335

493

DABCYL

453

-

MCA

328

393

DNP

348

-

Abz

330

420

DNP

348

-

Abz

330

420

Tyr (3-NO2)

360

-


6. Quotation and Ordering

Detailed workflows, technical specifications, and quotation information for customized fluorescent peptide services are available on our official website. Professional technical support will be provided to meet your research needs.


Aladdin: https://www.aladdinsci.com/

目录: 技术文章

Da — 若无特别说明,分子量单位默认为道尔顿。   Mw — 重均分子量。   Mn — 数均分子量。

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引用本文

阿拉丁科学.《Fluorescent-Labeled Peptides》. 阿拉丁知识库,更新于 2025年9月5日。 https://www.aladdin-e.com/zh_cn/faqs/fluorescent-labeled-peptides-en.html
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