Fluidity One-W Serum


Fluidity One-W Serum

Quantify protein interactions in complex backgrounds

Fluidity One systems offer a novel approach to determine affinity (KD), size, concentration, and stoichiometric information when a labeled protein interacts with DNA, lipids, antigens or other proteins

Characterize protein interactions in crude lysates, serum or plasma

Eliminate risk of binding artefacts or other surface constraints by measuring protein interactions directly in solution

Determine KD and concentration simultaneously

Measure antibody affinity profiles
directly in minimally diluted
serum or plasma

Comprehensively assess immune response

Quantify immune responses to antigens
Quantify viral neutralization capacity


What are customers saying about us

Don’t just take is from us, here is what are customers saying

Measure directly in complex sample backgrounds

Antibody-affinity profiling in serum – SARS-COV-2 anti-spike S1 antibody against SARS-CoV-2 RBD (receptor binding domain)

  • Measure close to physiologically-relevant conditions
  • Reduce or eliminate time-consuming purification steps
  • Minimize risk of dilution effects
  • Minimize sample consumption – 60-100 μL* sample per KD

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Results independent of sample background

Antibody-affinity profiling – SARS-COV-2 anti-spike S1 antibody against SARS-CoV-2 RBD

  • Measurements in buffer or complex backgrounds, provide corresponding results
  • Quantitative analysis of protein–protein interactions (KD and binding-site concentrations)
  • Determine affinity, KD, and absolute concentration of antibody binding sites

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Determine affinity and concentration with one technique

Immunoprofiling in serum during infection – Characterizing the immune response to viral infections


A collaboration with Prof. Adriano Aguzzi and Prof. Tuomas Knowles.

  • No correlation between affinity or concentration and disease severity – Hospitalized and non-hospitalized COVID-19 patients in same cluster
  • Affinity KD spans significantly wider range than concentration

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Take a closer look

Fluidity One-W Serum highlights

  • Generate data in close to physiologically-relevant conditions
  • Reduce or eliminate need for time-consuming purification
  • Determine KD and concentration directly in solution
  • Minimize sample consumption – typically 60 – 100 μL per KD
  • Reveal changes in molecular conformation

Fluidity One-W Serum specifications

  • System

    • Application

      Determine KD, and concentration in biological buffer systems or backgrounds such as serum or plasma

    • 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™ 647

    • Typical sample consumption to determine protein KD

      60 – 100 μL

    • Sample volume per datapoint

      5 μL

    • Compatibility

      Compatible with crude, complex backgrounds such as serum or plasma | Compatible with aqueous and biological buffers including components such as TRIS, HEPES, PBS, NaCl, KCl, TWEEN, DMSO and DMF.

    • Datapoints per run

      1 datapoint per run

    • Fluorescent labels

      Alexa Fluor™ 647 and equivalents | RFP and Cy5

    • Data export

      USB Mass Storage Device | Fluidity Cloud

    • Exported data file formats

      CSV, 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

Fluidic Analytics is changing how proteins are characterised

We're doing this with novel, cutting edge technology and a fantastic, committed team