Artist rendering analytical assay representation

CaptureSelect conjugated ligands are available for use in a range of analytical assays and can be used for the specific detection, quantitation, and characterization of antibodies, antibody fragments, proteins, hormones, and viral vectors. The affinity ligands are chemically conjugated to either biotin, HRP, or a fluorescent dye.

The biotinylated ligands are conjugated using an appropriate spacer that retains binding reactivity of the ligand when immobilized onto streptavidin-functionalized surfaces, thereby allowing for use in activation and kinetic assays.

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CaptureSelect technology

Conventional antibodies, such as immunoglobin G (IgG), are composed of a heavy chain and a light chain. In some species, the IgGs lack the light chain and are composed solely of the heavy chain, yielding a heavy-chain IgG (hc-IgG). CaptureSelect affinity ligands are created by a proprietary technology based on recombinant single domain antibodies. The ligand is a ~14 kDa single domain fragment (VHH) containing the three complementary determining regions (CDRs) that form the antigen binding domain (Figure 1).

To generate the VHH ligand, the heavy-chain antibodies are pared down to focus on only those parts that are important for binding an antigen, which includes the CDR. The VHH ligands maintain high affinity and specific antigen binding while being one-tenth the size of traditional antibodies. The VHH ligands are recombinantly expressed in the yeast Saccharomyces cerevisiae in a production process free of any animal components (Animal Origin-Free).

Artist rendering of CaptureSelect technology

Figure 1. A regular antibody (IgG) compared to a heavy-chain antibody (hc-Ig) lacking the light chains. CaptureSelect ligands are based on the single domain fragment (VHH) from these hc-IgGs. On the right side, a ribbon diagram of a VHH ligand is shown. The CDRs are indicated in red, green, and blue.

Ligand applications

CaptureSelect conjugated ligands can be used in multiple areas, such as discovery and screening, detection, quantitation, and other product or process analytics.

Applications can include:

  • Enzyme-linked immunosorbent assays (ELISA)
  • Bio-Layer Interferometry (BLI) assays
  • Surface Plasmon Resonance (SPR) assays
  • Immunoprecipitation
  • Western blot
  • Protein capture using magnetic beads
  • For examples, protocols, and publications highlighting the conjugated ligands, download the application guide or watch the webinar on the versatility of single domain antibody technology.

    Rendering of CaptureSelect ligand conjugate bonded to target protein

    Figure 2. Representation of a CaptureSelect biotinylated ligand bound to its target protein. The biotin molecules are chemically conjugated to the affinity ligand through a spacer, allowing immobilization on streptavidin-functionalized surfaces.


    Webinar: Demonstrating versatility of single domain antibody technology in the development of antibody therapeutics

    Watch this webinar to discover:

  • The versatility of single domain antibody (sdAb) technology in antibody drug development
  • The sdAbs which help increase efficiency of antibody purification
  • The development of analytical methods based on sdAb technology

    Watch now ›

  • CaptureSelect conjugated affinity ligands

    We have created an extensive list of ligands directed against:

  • Antibodies, fragments, and related derivatives
  • Proteins and hormones
  • Viral vectors

    You can find more detailed information on the selectivity and use of these products in the applications guide or by viewing the specific product pages linked below.

  • CaptureSelect conjugated ligands for antibodies and antibody fragments

    CaptureSelect ligandBiotinBiotin
    100 µg500 µg
    Anti-IgG-FC (hu)71032621007103262500
    Anti-IgG-CH171032021007103202500
    Anti-IgG-CH1XL7103462100  7103462500
    Anti-LC-Kappa(hu)71032721007103272500
    Anti-LC-Lambda(hu)71030821007103082500
    Anti-FLC-Kappa(hu)7103292100 7103292500
    Anti-IgG37103042100 7103042500
    Anti-IgG47102902100 7102902500
    Anti-IgA7102882100 7102882500
    Anti-IgM7102892100 7102892500
    Anti-IgE7103542100 7103542500
    Anti-IgG-FC(multi-species)7102852100 7102852500
    Anti-LC-Kappa(murine)7103152100 7103152500
    Anti-LC-Lambda(mouse)7103232100 7103232500
    Anti-IgG-FC (Rabbit)7103642100 7103642500

    CaptureSelect conjugated ligands for proteins and hormones

    CaptureSelect ligandBiotinBiotin
    100 µg500 µg
    Anti-Factor VII7102992100 7102992500
    Anti-Factor VIII7102862100 7102862500
    Anti-Factor IX7103002100 7103002500
    Anti-Factor X7103702100 7103702500
    Anti-AAT7102872100 7102872500
    Anti-Fibrinogen7102912100 7102912500
    Anti-HSA7102972100 7102972100
    Anti-Transferrin7103062100 7103062500
    Anti-HGH7103160100 7103160500
    Anti-FSH7103180100 7103180500
    Anti-Prothrombin7103452100 7103452500
    Anti-EPO7103372100 7103372500
    Anti-C1-Inhibitor7103402100 7103402500
    Anti-Gonadotropin7103412100 7103412500

    Recombinant protein detection and quantitation using C-tag

    CaptureSelect Biotin Anti-C-tag Conjugate consists of a 13 kDa VHH affinity ligand with high affinity and selectivity for the 4-amino-acid 'C-tag' peptide tag E‐P‐E‐A (glutamic acid-proline-glutamic acid-alanine).

    The Anti-C-tag affinity ligand recognizes the E-P-E-A peptide when this tag is fused directly to the C-terminus of a protein. The affinity ligand—constructed as a mono-specific bihead—is chemically conjugated to its specific label via an appropriate spacer that retains the binding reactivity of the ligand.

    CaptureSelect ligandBiotinBiotinAlexa Fluor 647
    100 µg500 µg
    Anti-C-tag7103252100 71032525007213252100  

    AAV total capsid ELISA with anti-AAV conjugated affinity ligands

    CaptureSelect Anti-AAVX Conjugate consists of a 14 kDA VHH affinity ligand. The fragment specifically binds with high affinity to adeno-associated virus particles (AAV). It demonstrates good binding reactivity towards a variety of AAV serotypes, including AAV1 to AAV8, and AAVrh10. The AAVX ligand is available with different labels, such as biotin, HRP, and Alexa Fluor 647. The biotinylated and HRP-conjugated ligands can be used to develop an AAV total capsid ELISA, to quantify the total number of capsids in an AAV culture or during the production and purification process.

    CaptureSelect conjugated ligands for viral vectors

    CaptureSelect ligandBiotinBiotinHRPAlexa Fluor 647
    100 µg500 µg
    Anti-AAVX7103522100710352250073035221007233522100
    Anti-AAV87103382100 7103382500--
    Anti-AAV97103332100710333250073033321007233322100 
    Anti-ADv57103532100 7103532500--

    The Human IgG-Fc PK Biotin Conjugate consists of a 13 kDa recombinant VHH affinity ligand, chemically conjugated to biotin. The ligand specifically binds to the Fc part of all four human IgG subclasses. The conjugate can be used for the detection, quantification, and characterization of all human (recombinant) IgG antibodies and Fc-fusion proteins in, for example, non-human plasma and/or serum samples like mouse, rat, rhesus, and cynomolgus monkey. This makes the conjugate very suitable for setting up pharmacokinetics (PK) assays.

    CaptureSelect human kinetics biotin conjugates are bi-functional ligand constructs consisting of two different recombinant VHH affinity ligands. These conjugates enable high-affinity capture of Human IgG Fab fragments that contain a kappa or lambda light chain. The bi-functional ligands are chemically conjugated to biotin, which allows immobilization on streptavidin-functionalized surfaces. They can be used for the screening of biomolecular interactions between Fab fragments and their specific target antigen. The kinetics ligands bind the CL-kappa or CL-lambda (light chain) and the CH1 domain (heavy chain) of a human IgG Fab fragment simultaneously. This binding results in extreme low dissociation rates (Kd) between the ligand and the captured Fab fragment.

    CaptureSelect conjugated ligands for kinetic experiments

    CaptureSelect ligandBiotinBiotin
    100 µg500 µg
    Anti-IgG-FC PK71033221007103322500
    Anti-Human Fab-Kappa Kinetics71033021007103302500
    Anti-Human Fab-Lambda Kinetics71033121007103312500


    CaptureSelect biotinylated ligands:

    Review our list of biotinylated ligands directed against antibodies and related derivatives. Find more detailed information on selectivity and use of these products in the product information sheets available for download on the specific product pages:

    Biotin Anti-IgG-CH1

    Binds human IgG and all Fab fragments thereof, through recognition of the CH1 domain on all four human IgG subclasses.

    Biotin Anti-IgG-Fc (Human)

    Binds human IgG, through recognition of the Fc region (CH3 domain) on all four human IgG subclasses.

    Biotin Anti-IgG-Fc (Multi-species)

    Binds IgG through recognition of the Fc region on IgG of multiple species. View product sheet for species coverage.
    Biotin Anti-IgG-Fc (Rabbit)Binds to rabbit IgG (immunoglobulin G) from recombinant and plasma sources. The ligand shows no cross-binding to bovine, horse, sheep, goat, mouse, rat, and human IgG. Moderate cross-binding was observed towards swine IgG.

    Biotin Anti-IgA

    Binds human IgA, IgA-dimers and secretory IgA (sIgA), through recognition of the Fc region on both human IgA subclasses.

    Biotin Anti-IgM

    Binds human, mouse and rat IgM.
    Biotin Anti-IgEbinds to human IgE (immunoglobulin E) from recombinant and plasma sources, through recognition of the Fc region (CH4 domain)

    Biotin Anti-LC-lambda (Human)

    Binds all human lambda light chains (LC), through recognition of the constant domain (CL-lambda) on any human antibody, Fab fragment or free light chain.

    Biotin Anti-LC-kappa (Human)

    Binds all human kappa light chains (LC), through recognition of the constant domain (CL-kappa) on any human antibody, Fab fragment or free light chain.   

    Biotin Anti-LC-kappa (Murine)

    Binds all mouse - and rat kappa light chains (LC), through recognition of the constant domain (CL-kappa) on any mouse and rat antibody, Fab fragment or free light chain.
    Biotin Anti-LC-lambda (Mouse) Binds all mouse lambda light chains (LC), through recognition of the constant domain (CL-lambda) on any mouse antibody, Fab fragment or free light chain
    Biotin Anti-LC-lambda (Rat) Binds all rat lambda light chains (LC), through recognition of the constant domain (CL-lambda) on any rat antibody, Fab fragment or free light chain

    Biotin Anti-IgG3 (Human)

    Binds human IgG3 without any cross-binding to other human IgG subclasses or antibody isotypes.

    Biotin Anti-IgG4 (Human)

    Binds human IgG4 without any cross-binding to other human IgG subclasses or antibody isotypes.

    Biotin Human Fab-kappa Kinetics

    High affinity capture of human IgG Fab fragments that possess a kappa light chain. Extreme low off-rates are achieved through avidity by targeting the CL-kappa domain of the Fab (light chain) and its IgG CH1 domain (heavy chain) simultaneously, thereby enabling Fab screening on target binding kinetics.

    Biotin Human Fab-lambda Kinetics

    High affinity capture of human IgG Fab fragments that possess a lambda light chain. Extreme low off-rates are achieved through avidity by targeting the CL-lambda domain of the Fab (light chain) and its IgG CH1 domain (heavy chain) simultaneously, thereby enabling Fab screening on target binding kinetics.

    Biotin Anti-Free LC-kappa (Human)

    Binds highly selective to free human kappa light chains and dimers thereof, through recognition of an epitope on the human CL-kappa domain that is masked in intact antibodies and Fab fragments, thereby providing a unique tool for specific detection and quantitation of free kappa light chains in (crude) antibody preps.

    Biotin Human IgG-Fc PK

    Binds highly selective to human IgG, through recognition of the Fc region on all four human IgG subclasses without cross-binding to mouse, rat, rhesus and cynomolgus monkey IgG, thereby making it extremely suitable for setting up pharmacokinetics (PK) assays.

    Review our list of biotinylated ligands directed against different proteins and virus particles. Find more detailed information on selectivity and use of these products in the product information sheets available for download on the specific product pages:

    Biotin Anti-C-tag

    Binds the short C-tag sequence E-P-E-A (glutamic acid - proline - glutamic acid – alanine) when this affinity tag is fused at the C-terminus of a target protein.

    Alexa Fluor™ 488 Anti-C-tag Binds the short C-tag sequence E-P-E-A (glutamic acid - proline - glutamic acid – alanine) when this affinity tag is fused at the C-terminus of a target protein.
    Biotin Anti-FXBinds to human Factor X and its activated form Factor Xa from plasma and recombinant sources

    Biotin Anti-FIX

    Binds recombinant as well as plasma derived human Factor IX (FIX)

    Biotin Anti-FVIII

    Binds recombinant (full length and B-domain deleted) as well as plasma derived human Factor VIII (FVIII), through recognition of the FVIII light chain.

    Biotin anti-FVIIBinds recombinant as well as plasma derived human Factor VII (FVII)
    Biotin Anti-Gonadotropin Binds to the alpha chain of recombinant as well as natural sourced hCG (human chorionic gonadotropin), LH (luteinizing hormone), TSH (Thyroid-stimulating hormone) and FSH (follicle-stimulating hormone)
    Biotin Anti-Human Albumin Binds recombinant as well as natural sourced human serum albumin (HSA) including HSA-fusion proteins
    Biotin Anti-AAT Binds recombinant as well as natural sourced human α1-Antitrypsin (AAT)
    Biotin Anti-C1-Inhibitor Binds recombinant as well as natural sourced human C1-Inhibitor (C1-inh, C1 esterase inhibitor)
    Biotin Anti-FibrinogenBinds recombinant as well as natural sourced human Fibrinogen (coagulation factor I, FI)
    Biotin Anti-Transferrin Binds recombinant as well as natural sourced human Transferrin
    Biotin Anti-α1-Acid Glycoprotein Binds recombinant as well as natural sourced human α1-Acid Glycoprotein (AGP) or Orosomucoid (ORM)
    Biotin Anti-Haptoglobin Binds recombinant as well as natural sourced human Haptoglobin (Hp)
    Biotin Anti-C3 Binds recombinant as well as natural sourced human Complement Component 3 (C3)
    Biotin Anti-vWF Binds recombinant as well as natural sourced human von Willebrand Factor (vWF)
    Biotin Anti-ApoA1 Binds recombinant as well as natural sourced human Apolipoprotein A1 (ApoA1)
    Biotin Anti-α2-Macroglobulin Binds recombinant as well as natural sourced human α2-Macroglobulin (A2M)
    Biotin Anti-Antithrombin III Binds recombinant as well as natural sourced human Antithrombin III (ATIII)
    Biotin Anti-Prothrombin Binds recombinant as well as natural sourced human Prothrombin (coagulation factor II, FII)

    Biotin Anti-hGH

    Binds recombinant as well as natural sourced human Growth Hormone (hGH).

    Biotin Anti-GCSF

    Binds recombinant as well as natural sourced human Granulocyte-Colony Stimulating Factor (G-CSF)

    Biotin Anti-FSH

    Binds recombinant as well as natural sourced human Follicle Stimulating Hormone (FSH), through recognition of an epitope specific for intact FSH only.

    Biotin Anti-Insulin
    Binds recombinant and natural-sourced human insulin and shows similar binding reactivity towards porcine- and bovine-sourced insulin. It also binds to human proinsulin, the precursor of insulin that still contains the C-peptide.
    Biotin Anti-EPOBinds recombinant and natural-sourced human Erythropoietin (EPO).
    Biotin anti-AAV8Binds with high affinity to Adeno-associated virus particles of serotype 8 (AAV8). Note that it may cross-bind towards other AAV serotypes.
    Biotin anti-AAV9Binds with high affinity and selectivity to Adeno-associated virus particles of serotype 9 (AAV9)
    Biotin anti-AAVXBinds with high affinity and selectivity to adeno-associated viral (AAV) particles of a wide variety of serotypes.
    Biotin anti-Adv5Binds with high affinity and selectivity to recombinant hexon capsomeres of Adenovirus serotype 5 (AdV5) particles as well as free hexon proteins thereof

    Bioprocessing resources

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