Application note

Determination of KD of aptamer protein interactions by microfluidic diffusional sizing

While methods exist to determine KD experimentally, reviews remark that these often require a degree of expertise to collect reliable data and can have technique specific limitations


  • MDS requires no surface fixing, and no complex preparation steps – allowing binding to be observed rapidly and in near-native conditions.
  • MDS is simple and rapid – with no calibration, specialist preparation or setup required.
  •  Measuring size gives confirmation of on-target binding, by quick comparison of the expected and observed size.


  • Publications and resources

    View all
    • Infographic

      The KD cheat sheet

      This printable "cheat sheet" gives an overview of what KD, the dissociation constant, means, how to calculate it, and how to experimentally measure it.

    • Documentation

      Fluidity One and One-W comparator

      This overview document quickly outlines the differences between our Fluidity One and Fluidity One-W instruments.

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