HORIBA SFA-20 Stopped Flow Device


SFA-20 Stopped Flow Device

The SFA-20/SPEX series of stopped-flow rapid-kinetics accessories offers versatility for spectroscopic monitoring of fast reactions in solution. 
What is it? 
  • One of the most frequently used rapid kinetics techniques. 
  • Used to study fast kinetics reactions (in the millisecond timescale) between two mixed reactants. 
  • Many applications in the chemistry and biochemistry fields. 
  • Quenching studies 
  • Energy transfers 
  • Enzymes kinetics 
    How does it work? 
  • Under pneumatic drive activation, the two small volumes of solutions are driven from high performance syringes through a high efficiency mixer. 
  • The resultant mixture passes through a measurement flow cell and into a stopping syringe. 
  • Just prior to stopping, a steady state flow is achieved. 
  • As the solution fills the stopping syringe, the plunger hits a block, causing the flow to be stopped instantaneously. 
  • Using appropriate techniques, the kinetics of the reaction can be measured in the cell.
  • SFA-20 Stopped Flow Device
    Additional Specifications Dead Time: 
    <8 ms 
    Dead Volume: 
    700 µL (SFA-20 and SFA-20mx); 350 µL (SFA-20M and SFA-20mxM) 
    Window Sizes: 
    3 mm wide 
    Flow cell's beam height:
    15 mm from base of cell to center of window 
    Min. vol. per determination: 
    100 µL per reactant 
    Observation path: 
    3 mm for excitation and 3 mm for emission 
    Observation cell: 
    Fill-syringe volume: 
    3 mm wide x 10 mm high for excitation and emission, specifically designed for FluoroMax® and FluoroLog® instruments 
    Adjustable stop volume: 
    Mixing ratio: 
    Up to 20:1 
    Temperature range: 
    5 - 80°C 
    Piston Drive: 
    Manual drive is standard; Pneumatic control optional. We recommend, however, the SFA-20mx/SPEX and SFA-20mxM/SPEX Umbilical length = 600 mm (SFA-20/SPEX and SFA-20mx/SPEX); 300 mm (SFA-20M/SPEX and SFA-20mxM/SPEX); other lengths on request 
    Drive syringes: 
    2.5 mL for SFA-20/SPEX; 1 mL for other models High-efficiency T-format mixer: Available for SFA-20/SPEX and SFA-20M/SPEX; 10 µL delay available for SFA-20mx/SPEX and SFA-20mxM/SPEX; longer delays upon request


  • Dead time < 8 ms 
  • Observation cell optimized for best performance with SPEX® instruments 
  • Integrates into any current SPEX® fluorescence system 
  • Multi-mixing ability 
  • Flexible thermostat format 
  • Sample’s path constructed of chemically inert Kel-F™, silica, Teflon®, and glass 
  • Crush-resistant flexible umbilical
  • Photos

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