Single B-cell Antibody Service

Custom recombinant antibody development

Active Motif offers custom rabbit antibody development services unlike any other, combining our single B-cell cloning technology to profile the antigen-binding capacity of antibodies produced by individual B cells and further optimizing them by applying our own AbFlex® technology to deliver highly specific recombinant antibodies that contain functionally powerful features.

AbFlex® recombinant antibodies may be conjugated to a range of dyes, enzymes, beads, oligonucleotides and other tags for a range of applications in drug discovery.

Advantages of the AbFlex® antibody technology are its flexible labeling and purification options. Each AbFlex® antibody contains:

  • Sortase recognition motif (LPXTG) to covalently add fluorophores, enzymatic substrates (e.g., HRP), peptides, DNA, drugs, or other labels in a directed, reproducible manner.
  • 6xHis tag, which can be used with nickel-based purification systems.
  • A biotinylation tag sequence for enzymatic biotin conjugation using the biotin ligase, BirA.
AbFlex antibody with flexible labeling and purification options
Single B-cell Cloning Technology

Active Motif Single B-cell Service Includes:

  1. Customer provided antigen / screening material
  2. Rabbit Immunization or client provides PBMCs or spleen cells
  3. B-cell Isolation & Antibody Cloning
  4. Primary Characterization – includes Antibody Ranking
  5. Development of Expression Vector(s)
  6. Small Scale Expression


  • Final, delivered antibodies contain all AbFlex labeling tags for 6XHis Tag, Biotinylation, and Sortase A5. Active Motif does not offer custom expression of antibodies with alternative labeling tags or directly-conjugated as a final product. For custom B-cell cloning projects to deliver a final antibody without all tags, please inquire.
  • AbFlex recombinant antibodies are currently generated in a rabbit heavy chain (Fc) backbone only.
  • Antibodies are not provided in sterile-manufactured, sterile-filtered, or low endotoxin (low EU) format.

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