Affimer® Technology

Affimer® proteins are small, single domain binding proteins which are based on Stefin A (or Cystatin A in plants). They are a more stable alternative to antibodies that are ideal for use in diagnostic applications. A large binding surface, obtained through two 9 amino acid loops, enables Affimer proteins to bind with high affinity and exquisite selectivity. At 12-14 kDa, Affimer® molecules are around 10 times smaller than antibodies, giving several performances advantages such as increased packing density on surfaces and greater proximity to sensor surfaces.

Why use Affimer® reagents for your diagnostic development?


  • Affimer® reagents are ideal tools for use in diagnostic test development, due to being highly specific, reproducible, stable, and easy to manufacture at scale.
  • With a rapid development timeline, Affimer® reagents represent a quick solution to the ever growing need for high quality diagnostic reagents with consistent supplies.
  • Affimer® technology offers highly specific target recognition in a variety of complex samples, while retaining both chemical and thermal stability.
  • Affimer® molecules offer flexibility in formatting via both genetic and chemical means.
  • A single strategic cysteine residue addition allows for site specific functionalisation with enzymes, dyes, fluors, or immobilization onto a variety of surfaces.