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Fluorescent Labelling with Texas Red | LifeTein Peptide Blog

Fluorescent labeling is a powerful technique used in cell biology and microscopy to visualize specific molecules within cells. Among the various fluorophores available, Texas Red stands out as a bright red-fluorescent dye commonly used for cellular imaging app

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This guide cannot diagnose a condition or recommend a personal treatment plan. Discuss medical questions with a qualified professional.

Fluorescent labeling is a powerful technique used in cell biology and microscopy to visualize specific molecules within cells. Among the various fluorophores available, Texas Red stands out as a bright red-fluorescent dye commonly used for cellular imaging applications. It holds many vital applications in biological research.

Texas Red: Properties and Applications

Bright Fluorescence: Texas Red emits a vibrant red fluorescence when excited by laser lines at 561 or 594 nm. Its brightness makes it ideal for detecting weakly expressed antigens or proteins in biological samples.

Conjugation to Antibodies and Peptides: Researchers often conjugate Texas Red to antibodies or peptides. When these labeled molecules bind to specific targets (such as antigens), they reveal the location of those targets within cells.

Photostability: Texas Red exhibits good photostability in buffer and antifade conditions, allowing for reliable imaging over extended periods.

Alternative: Alexa Fluor 594: For even brighter and more photostable conjugates, consider using Invitrogen Alexa Fluor 594. It shares spectral properties with Texas Red but offers improved solubility and sensitivity.

Find more about Peptide Synthesis here.

Key Takeaways

Texas Red is a red-fluorescent dye commonly used for cellular imaging.

It is conjugated to antibodies and proteins to visualize specific targets within cells.

Researchers can choose between Texas Red and Alexa Fluor 594 based on their specific imaging needs.

Intracellular Localization Studies

Texas Red-labeled antibodies and peptides have been instrumental in studying the localization of specific molecules within cells. By targeting specific antigens or proteins, researchers can visualize their distribution in various cellular compartments:

Nucleus

Texas Red-conjugated antibodies against nuclear proteins (e.g., histones) allow precise visualization of the nucleus. This aids in understanding chromatin organization and gene expression.

Cytoskeleton

Texas Red-labeled phalloidin binds to actin filaments, revealing the intricate cytoskeletal network. Researchers use this to study cell motility, shape changes, and intracellular transport.

Membrane Proteins

Texas Red-labeled antibodies against membrane proteins (e.g., receptors) help identify their presence on the cell surface. This is crucial for signaling studies and drug development.

Multicolor Imaging

Texas Red is often used in multicolor experiments alongside other fluorophores. Combining it with green (e.g., FITC) or blue (e.g., DAPI) fluorophores allows simultaneous visualization of multiple targets within the same sample.Find more Fluorescents here.

Frequently Asked Questions

What is Texas Red?

Texas Red is a red-fluorescent dye commonly used in cell biology and microscopy. It emits bright red fluorescence when excited by specific laser lines, making it ideal for visualizing specific molecules within cells.

How is Texas Red used in research?

Intracellular Localization Studies: Texas Red-labeled antibodies and proteins help researchers study the distribution of specific molecules within cellular compartments.

Can Texas Red be used alongside other dyes?

Yes, Texas Red can be used in multicolor experiments alongside other fluorophores. Combining it with different colors allows researchers to study multiple targets simultaneously.

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Helpful context for this guide

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Research context

Read sources and limitations before applying a claim.

Are Cy7-labelled peptides available commercially for research?

Yes, specialized providers such as LifeTein offer custom synthesis of Cy7-labelled peptides with high purity (>95%) and rigorous analytical validation. These products are suitable for in vivo imaging, flow cytometry, and advanced techniques like LIPSTIC. Long, L., Cao, X., Shi, X., Zhang, J., & Shi, C. (2025). Modifications and applications of heptamethine cyanine (Cy7) dyes as near-infrared photosensitizers. Coordination Chemistry Reviews, 541, 216780. https://doi.org/10.1016/j.ccr.2025.216780 Khaikate, O., Muangsopa, P., Piyanuch, P., Khrootkaew, T., Wiriya, N., Chansaenpak, K., Sukwattanasinitt, M., & Kamkaew, A. (2024). Asymmetric heptamethine cyanine dye for viscosity detection and photodynamic therapy. Journal of Photochemistry and Photobiology A: Chemistry, 453, 115659. https://doi.org/10.1016/j.jphotochem.2024.115659

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Protein-Protein Interaction Studies

In FRET-based assays, TAMRA acts as an acceptor dye paired with donors like fluorescein. This configuration allows detection of molecular interactions between labeled peptides and target proteins. For instance, TAMRA-labeled kinase substrate peptides can reveal enzymatic activity by quantifying changes in FRET efficiency upon phosphorylation. Find other fluorescent pairs here.

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Practical and safety references

These excerpts are educational, not personalised medical instructions.

How-to reference

How to solubilize my synthetic peptides? #

Please refer to this FAQ for details: Handling and Storage of Synthetic Peptides. If the peptides are still cloudy, or turbid, you may have reached the limit of solubility. When the peptides are insoluble in the buffer, please try to sonicate, centrifuge, and lyophilize the peptide. Make sure to break the lyophilized lumps into a fine powder. Then try a small volume of a good agent 8M Urea, NMP, DMF, or DMSO to dissolve the peptide. Then dilute with water or your desired buffer. For peptides with Arg or LYs, you should try to lower the pH to 6 because the protonated amino acids will help solubility. Sonication and the following solvents may help with difficult peptides: 1) Begin with 100 % acetonitrile then dilute with water until 50% 2) Begin with 100% DMSO then dilute with water until 30 % 3) Dissolve it with 8M Urea 4) Dissolve it with 6 or 8 M Guanidine hydrochloride 5) 6M GuHCL, 0.05% TFA, pH2, 6) 100% TFA 7) 40% AcOH, 30%ACN, 30% water

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Storage reference

Storage temperatures and conditions #

For many of our antibodies, freezing at -20 C or -80 C in small aliquots is the optimal storage condition. Aliquotting minimizes damage due to freezing and thawing, as well as contamination introduced by pipetting from a single vial multiple times. Aliquots should be no smaller than 10 µl. Upon receiving the antibody, centrifuge at 5,000 x g for 30 seconds to pull down the solution, and transfer aliquots into low-protein-binding microcentrifuge tubes. Antibodies should be frozen as soon as possible, storage at 4 C upon receipt of the antibody is acceptable for one to two weeks, followed by freezing for long-term storage. To prevent microbial contamination, sodium azide can be added to an antibody preparation to a final concentration of 0.02% (w/v). If using antibodies for in vivo studies, please be sure to use preparations that do not contain sodium azide. This antimicrobial agent blocks the cytochrome electron transport system. Sodium azide will interfere with any conjugation that involves an amine group and should be removed before proceeding with the conjugation. After conjugation, antibodies can be stored in sodium azide but 0.01% thimerosal (Merthiolate), which does not have a primary amine, is an acceptable alternative. Sodium azide can be removed from antibody solutions by dialysis or gel filtration. The molecular weight of IgG is 150,000 daltons (IgM is ~ 600,000); the molecular weight of sodium azide is 65 daltons. A micro-dialysis unit with a cut off at 14,000 dalt…

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Peptide Therapy Guide Editorial Team

Editorial team for Peptide Therapy Guide.

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