Fluidity One-W


Fluidity One-W

Quantify and characterize any protein interaction in solution –
even with challenging targets

The Fluidity One-W system enables quantification and characterization of any protein interaction – in solution and even with challenging targets

Determine size, KD, concentration and stoichiometry in solution

  • Determine KD and concentration simultaneously
    • Control for off-target binding and false positives
  • Verify identity of a complex
    • Confirm interaction partners via absolute size (hydrodynamic radius, Rh) measurements
    • Infer stoichiometry of interaction
  • Analyze interactions in solution
    • Eliminate risk of binding artefacts or other surface constraints

PD-1/PD-L1 interaction – critical in control of autoimmune response

Data in agreement with reported literature


Protein-DNA interaction

KD of aptamer-protein interactions


Reveal changes in molecular conformation

Changes in hydrodynamic radius in solution: Protein A:IgG interaction


Take a closer look

Fluidity One-W highlights

  • Uses microfluidic diffusional sizing (MDS) technology to measure changes in molecular size (hydrodynamic radius) as binding events occur
  • Enables development of customized protocols to study a wide range of interactions – typical run time 8-14 minutes per datapoint
  • Minimizes consumption of precious samples – 5 μL per datapoint, 60-100 μL to determine KD

Register your interest

Complete the form below to register your interest in the Fluidity One platform.

Fluidity One-W specifications

  • System

    • Application

      Determine size, KD and stoichiometry in aqueous buffer systems

    • Technology

      Microfluidic Diffusional Sizing (MDS)

    Interaction analysis

    • Run time

      Typically 8 – 14 min per datapoint

    • Size range: hydrodynamic radius, Rh

      1 – 20 nm

    • Accuracy of size determination

      ± 10%

    • Reproducibility of size determination

      CV < 10%

    • Working range molecular weight

      1.4 kDa – 14 MDa

    • Sensitivity range (labeled HSA in PBS)

      1 nM – 1 μM Alexa Fluor™ 488

    • Typical sample consumption to determine protein KD

      60 – 100 μL

    • Sample volume per datapoint

      5 μL

    • Compatibility

      Compatible with aqueous buffer systems

    • Fluorescent labels

      Alexa Fluor 488 and equivalents | GFP and FITC | Fluidiphore labeling kit (fluidiphore rapid amine 503)

    • Data export

      USB Mass Storage Device | Fluidity Cloud

    • Exported data file formats

      CSV and JSON formats

    • Data output from Fluidity Cloud

      Result tables, binding curves and affinity (KD), size (Rh) of complex and labeled species


    • Consumables

      Kits containing chips and cartridges sufficient for 96 or 288 datapoints


    • Temperature control


    • Operating environment

      5 °C to 40 °C

    • Power requirements

      100 – 240 V AC, 50 – 60 Hz

    • Safety and EMC standards

      Designed to comply with all relevant safety and EMC standards


    • Dimensions (D x W x H; mm)

      400 x 400 x 430

    • Weight (kg)

      15 kg

Download the Fluidity One-W specification sheet

The Fluidity One platform enables quantification and characterization of any protein interaction –

even in complex backgrounds or with challenging targets

find out more