Service Search Product Search Gene Search
HOME

SERVICES

• Protein Biotinylation Service • Custom Lysate Preparation Service • Immunogenicity Test Service > Anti-Drug Antibody (ADA) Evaluation Service > Neutralizing Antibody (NAb) Test Service • Anti-Drug Antibody (ADA) Evaluation Service • Neutralizing Antibody (NAb) Test Service • Thanksgiving Day Sale • Enzyme Target & Activator & Inhibitor Screening Service • GPCR Screening Service • Ion Channel Screening Service • Bio-layer Interferometry (BLI) Service • Electrophoretic Mobility Shift Assay (EMSA) Service • Transcription Factor Analysis > Electrophoretic Mobility Shift Assay (EMSA) Service > Chromatin Immunoprecipitation (ChIP) Assay Service > DNase I Footprinting Assay Service • Transporter Screening Service • Chromatin Immunoprecipitation (ChIP) Assay Service • Enzyme Activity Assay Service • DNase I Footprinting Assay Service • Co-Immunoprecipitation (Co-IP) • Surface plasmon resonance (SPR) Service • Pull Down Assay • Protein Mutant Library Construction • C1 Expression System • Protein Conjugation Service on Beads • Bacteria Expression • Yeast Expression • Mammalian Cell Expression • Insect Cell Expression • Animal-free Expression • Cell-free protein expression • Large-scale Protein Production • PEGylation Services • Basic Protein Characterization • Protein Labeling • Stable Cell Line Construction for Protein Expression • Protein Mutagenesis • Protein Interaction Analysis Services > Bio-layer Interferometry (BLI) Service > Co-Immunoprecipitation (Co-IP) > Surface plasmon resonance (SPR) Service > Pull Down Assay > Yeast Two-Hybrid Screening > Membrane-based Yeast Two-Hybrid Screening > CLIP-Seq Service > Protein Binding Site Mapping • Yeast Two-Hybrid Screening • Membrane-based Yeast Two-Hybrid Screening • Recombinant Protein or Antibody Production • Protein Expression Systems > Nicotiana tabacum Expression System > Bacterial Expression Systems(E. coli / Bacillus) > Yeast Expression Systems(P pastoris / S cerevisiae) > Baculovirus-insect Cell Expression Systems > Mammalian Expression Systems(CHO / 293) • PEGylation Services • Stable Cell Line Construction for Protein Expression • Process Development • cGMP Manufacturing • QC and QA • Bacterial Manufacturing • CLIP-Seq Service • Protein Binding Site Mapping • Quantum Dot Labeling • Protein Expression > Custom Lysate Preparation Service > C1 Expression System > Protein Co-expression Service in E. coli System > Protein Co-expression Service in Mammalian Cells > Trimeric Protein Production Service • Protein Co-expression Service in E. coli System • Protein Co-expression Service in Mammalian Cells • NovEgg Expression System • ADME/Tox Prediction • Pharmacophore Modeling • Screening and Profiling Services > Enzyme Target & Activator & Inhibitor Screening Service > GPCR Screening Service > Ion Channel Screening Service > Transporter Screening Service • Trimeric Protein Production Service Nicotiana tabacum Expression System

CONTACT US

Tel: 1-631-448-8149
Fax: 1-631-938-8127

Quantum Dot Labeling

Labels, including fluorophore, biotin, enzymes, and radioactive isotopes, have greatly contributed to research in molecular biology, cell biology and biochemistry. Various labels have been used to detect, identify, track and sort biomolecules, and to facilitate the study of molecular structure and interactions. A new type of labeling, quantum dot labeling (QD), has draw a lot of attention recently. QD is a type of fluorescent semiconductor nanocrystals with unique optical and electrical properties due to its quantum effect and size effect. It has been widely used in many fields of life science.

Advantages:

  Size-tunable light emission and improved signal intensity
  Resistance to photobleaching
  Simultaneous excitation of multiple fluorescence colors
Quantum Dot Labeling

QD nanocrystal is nanometer-scale atom cluster, which is completely different with traditional fluorophore.

QD used in bio-research is colloidal nanocrystal. The most popular QD for biological applications is made of Cadmium mixed with Selenium cores coated with a layer of zinc sulfide.

QD nanocrystal can be coupled to proteins, oligonucleotides through bio-conjugation, such as streptavidin/biotin and protein A/Fc. It is an excellent replacement of traditional dyes due to its special optical properties. Conjugation of QDs to protein can be achieved by three various methods: i) use of EDC (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide,); ii) direct binding using thiolated peptides or polyhistidine residues; iii) absorption or non-covalent self-assembly using engineered proteins.

The emission of QD nanocrystal is narrow and symmetric, therefore allowing multiple colors to be used simultaneously, leading to its wide application in cellular labeling, tissue imaging and other biochemical assays.

Profacgen provides a wide range of QD conjugation strategies to meet the specific requirements of your projects. Please feel free to contact us for more information.

Reference

1 Zhao M., Zeng E., (2015). Application of functional quantum dot nanoparticles as fluorescence probes in cell labeling and tumor diagnostic imaging. Nanoscale Research Letters. 10: 171.
2 Medintz I., Uyeda H., Glodman E and Mattoussi H., (2015). Quantum dot bioconjugates for imaging, labeling and sensing. Nature Materials. 4: 435-446 
CONTACT US
Email: info@profacgen.com
Tel: 1-631-448-8149
Fax: 1-631-938-8127
Address: 45-1 Ramsey Road, Shirley, NY 11967, USA