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Information

Home Algae's crosslinked APC provides a convenient way to conjugate Allophycocyanin (APC) to antibodies. APC belongs to the phycobiliproteins family of highly soluble and fluorescent proteins derived from cyanobacteria and eukaryotic algae. APC, an ultra-sensitive fluorescent tracer with high emission quantum yields, emits in the near-infrared fluorescence range. It, therefore, avoids interference from autofluorescence of cellular components and other biological materials.

APC is significantly more sensitive than conventional organic fluorophores and has been used in applications such as Flow Cytometry, Homogeneous FRET assay, and Immunoassays.

 

Home Algae's crosslinked APC is an SH-reactive ready-to-use reagent. Modified Allophycocyanin has Maleimide groups that easily react with SH groups of a target antibody without the need for an additional activation.

Crosslinked APC
*with Ammonium Sulfate
  • Are phycobiliproteins stored in PBS only and in PBS with ammonium sulfate different?
    PBPs in different buffer solutions both exhibit good long-term stability, the form with ammonium sulfate requires more purification processes, such as dialysis or sulfate precipitation, to fully remove the ammonium sulfate prior to making tandem dyes and antibody conjugations. Home Algae Biotech offers phycobiliproteins stored in PBS only and PBS with ammonium sulfate buffer solutions.
  • Is the conjugation reaction linking the R-PE/APC to free sulfhydryl groups on the antibody?
    Home Algae's R-PE & APC Labeling Kit are SH-reactive labeling kits. Crosslinked R-PE and APC have maleimide (-NH2) groups that easily react with sulfhydryl (-SH) groups of target antibody without the need for additional activation. The maleinide group of R-PE/APC and sulfhydryl group on the antibody form a covalent bond during conjugation. Users can also use crosslinked R-PE & APC to label other molecules that have free sulfhydryl groups.
  • Do I need to remove the free R-PE from the R-PE-antibody conjugate?
    After the conjugation procedures, reaction mixture should contain mostly the R-PE-antibody conjugate, with small amounts of unconjugated R-PE and antibody. Unconjugated R-PE should not interfere with the assay result. However, purification is suggested for labeling up to 1 mg of antibody. Please contact us for more technical advice.
  • Can I purchase large pack of labeling kit and separate them into small vials on my own for several reactions?
    Yes, all pack sizes of our labeling kits are scalable and can be separated into small packs based on your experiment requirements.
  • What are the molecular weight of purified R-PE and APC?
    The molecular weight of purified R-PE is 240 kDa, and for purified APC is 105 kDa. They are both perfect for detecting cell surface antigens to further conduct cell screening and cell imaging. With high molecular weight, PE and APC won't penetrate into the cell sample even if cell membrane ruptured, which greatly lower the risk of false-positive reaction. It should be noted that the relatively high molecular weight of R-PE may preclude its use in procedures requiring good penetration into cells and tissues. It is predominantly intended for surface labeling of cells for flow cytometry.
Benefits of APC
  • Ideal for multi-color fluorescent staining

    • Applied to most fluorescence-based instruments

    • Significant stokes shifts with resolvable emission spectra

  • Ensure result accuracy

    • Bright Index: Level 4 with high quantum yield

    • It should be noted that the relatively high molecular weight of APC may preclude its use in procedures requiring good penetration into cells and tissues. It is predominantly intended for surface labeling of cells for flow cytometry.

  • Stability

    • Minimal fluorescence quenching

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