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HTRF MAb Anti FLAG M2-Eu cryptate, 20,000 Assay Points

Eu cryptate-labeled anti-FLAG M2 antibody for capturing FLAG M2-tagged proteins in protein/protein interaction assays.

For research use only. Not for use in diagnostic procedures.
Part Number: 61FG2KLA
Unit Size: 5,000 Assay Points
Part Number: 61FG2KLB
Unit Size: 20,000 Assay Points
  • MAb Anti FLAG M2-Eu cryptate is an IgG1 raised against FLAG® fusion proteins labeled with Eu. Unlike anti-FLAG®M1 antibody, the M2 antibody will recognize the FLAG® sequence at the N-terminus or C-terminus of FLAG® fusion proteins.

    This reagent can be used in both biochemical and cellular formats to study a wide variety of interactions: protein/protein, protein/peptide, protein/DNA, protein/RNA, protein/carbohydrate, protein/small molecule, receptor/ligand.

    HTRF can detect a broad range of affinity constants ranging from picomolar to low millimolar.

  • Assay Points
    Assay Target Type
    Fluorescent reagent
    Assay Technology
    Shipping Conditions
    Shipped Ambient
    Therapeutic Area
    Infectious Diseases
    Oncology & Inflammation
    Rare Diseases
    Unit Size
    20,000 Assay Points
  • Assay principle

    In an HTRF interaction assay, one partner is labeled (directly or indirectly) with the donor, and the other with the acceptor (again, directly or indirectly). The intensity of the signal is proportional to the binding of the 2 partners. In the example shown here: MAb Anti FLAG M2-Eu cryptate binds to the FLAG M2 tagged partner A while partner B* binds to a specific Ab labeled with an HTRF acceptor. *partner B can also be biotinylated, tagged, Fc fused. In these cases, use the corresponding HTRF reagent (anti-Tag, anti-species, protA, Streptavidin) labeled with acceptor for the detection.

    HTRF MAb Anti FLAG M2-Eu cryptate 1.svg


    Assay protocol

    The example on the right describes the protocol using a 20 µL final assay volume for detecting an interaction between a FLAG M2-tagged partner A and a non-tagged partner B*. Dispense the 2 partners (10 µL), incubate, add MAb Anti FLAG M2-Eu cryptate (5 µL) and anti-partner B labeled with acceptor (5 µL), incubate and read. *partner B can also be biotinylated, tagged, Fc fused or directly labeled. In these cases, use the corresponding HTRF reagent (anti-Tag, anti species, protA, Streptavidin) labeled with acceptor for the detection.

    HTRF MAb Anti FLAG M2-Eu cryptate 2.svg


  • How do the number of tests relate to active moiety?

    The average conjugate quantity per well reflects overall biological material content. Using the active moiety amount is generally preferred to the quantity of total conjugate. For Cryptate and d2 conjugates, the total conjugate amount equals that of the active moiety, since the molecular weight of the label is negligible. This is not the case for XL665 labeled entities for which the quantity of total conjugate will vary depending on the final molar ratio of the XL665 conjugate, however, the amount of active moiety, provided by Revvity, is constant and based on the number of tests ordered.

    HTRF MAb Anti FLAG M2-Eu cryptate 3.svg


    Recommended quantities of Cryptate and XL665 conjugates

    Cryptate conjugates must not be excessive in order to prevent reader saturation and an unacceptable level of background. In most cases, a cryptate concentration of 1 to 5nM is appropriate, and will generate 20,000 to 80,000 cps at 620 nm depending on the HTRF compatible reader used. The XL665 conjugate must match its assay counterpart as closely as possible in order for the maximum number of biomolecules to be tagged with the XL665 acceptor. Thus, to detect a tagged molecule at an assay concentration of 20nM, the concentration of anti-Tag-XL665 should be equimolar or higher.


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HTRF solutions, guide to major applications

This guide provides you an overview of HTRF applications in several therapeutic areas.