SX Sequential Mixing Accessory

Study reactivity of intermediate and transient species

The SX sequential- (or double-) mixing accessory is specifically designed to study the reactivity of intermediate and transient species. Asymmetric double mixing experiments are also fully supported to study, for example, protein folding/unfolding reactions.

  • Functions across the full range of SX detection modes
  • Full information with each experiment: drive profiles, calculated age time, drive volume per syringe, measurement of dead-time
  • Aging times reproducible to within 1ms
  • No hardware reconfiguration when switching between short and long aging times
  • Enter the required aging time through the software in the range 14ms to 1000s.

This accessory equips the sample handling unit with two drive rams (and 4 syringes). The first drive mixes two reagents (A and B) into an aging loop and, after a user defined aging period, a second drive mixes the aged solution with a third reagent (C) in the stopped-flow cell.


SX Direct Coupled Photodiode Array Detector

Efficient light collection for absorption measurements

The SX Direct Coupled Photodiode Array Detector ensures highly efficient light collection for stopped-flow absorption measurements. Well suited to measurement of redox reaction kinetics in which there are often absorption changes at more than one wavelength.

  • Enables acquisition of sets of time-resolved spectra from a single stopped-flow drive.
  • A 256 array that can acquire up to 1500 spectra per second
  • Available in two wavelength ranges: PDA-UV (285-725nm) and PDA-Vis (330-1100nm).
  • A self-contained spectrograph configured in a few seconds - no need to realign or recalibrate the s
  • High light intensity, stability and long lifetime
  • Simple, robust design and very small footprint

SX Fluorescence Polarization

Detect changes in mobility and environment of a fluorophore

Fluorescence polarization/anisotropy can provide information about changes in the mobility and environment of a fluorophore when it interacts with other molecules. Excitation of a fluorophore with plane polarized light results in the preferential excitation of molecules with their absorption moments orientated parallel to the plane of polarization.

  • Easy to fit, dual channel T-format fluorescence polarimeter with a movable calcite input polarizer and DPUV sheet collection polarizer
  • Control G-factor determination from the software
  • Acquire kinetic and spectral data in polarization, anisotropy, total emission and raw data (parallel and perpendicular) modes
  • Full post-acquisition conversion possible between data modes
  • Filter holders built into collection pieces to reduce scattered light
  • Filter holder built into excitation assembly, for additional flexibility with respect to wavelength selection and rejection
  • Straightforward set-up - no optimization required
  • Robust construction ensures consistent polariser alignment
  • Compatible with standard Xe and LED light sources
  • Requires pre-installation of SX Dual Fluorescence Detection (included as standard in recent systems)

SX Dual Fluorescence Detection Device

Simultaneously acquire fluorescence data from two detectors

The SX Dual Fluorescence Detection Device comprises an additional detection channel, fluorescence detector and cable to enable simultaneous fluorescence detection at two emission wavelengths. Both detectors are mounted directly onto the cell-block. Alternatively, to allow selection of the emission wavelength directly from the control software. one of the fluorescence detectors can be mounted on a second emission monochromator if the system is fitted with the SX Scanning Emission Monochromator.

  • Simple mounting to the sample handling unit cell block/emission mono
  • No need for hardware reconfiguration while switching back to single channel mode
  • Variety of cut-off and interference filters available
  • Possibility to use in tandem with SX SEM accessory for emission spectra recording

SX Scanning Emission Monochromator

Automated acquisition of equilibrium and time-resolved fluorescence spectra

As a second programmable monochromator, the SX Scanning Emission Monochromator enables automated acquisition of equilibrium and time-resolved fluorescence spectra.

The standard fluorescence configuration, with the fluorescence detector mounted directly onto the cell-block, has exceptional sensitivity, using a cut-off filter to block scattered light of the excitation wavelength such that only the fluorescence emission signal is detected. Experimental capabilities are extended by addition of a second programmable monochromator to enable selection of the detected emission wavelength from the control software.

  • Exceptional sensitivity
  • Filters out all except fluorescence emission signal
  • Automated acquisition of time-resolved emission spectra
  • Acquisition of steady-state emission spectra

Pro-KIV Kinetic Global Analysis

For analysis of multiwavelength kinetics

Pro-KIV Kinetic Global Analysis enables global analysis of data obtained when studying wavelength-dependent reaction kinetics or time-dependent spectra. Multiwavelength data is globally analyzed by fitting the entire dataset to a given reaction model using non-linear regression analysis.

Singular value decomposition (SVD) on multiwavelength data can identify where the main spectral changes are occurring. Isolating those components that contribute only random noise to the data can improve data quality.

The software may also be used to fit other kinetic data such as single wavelength absorbance and fluorescence data or provide kinetic data simulations based on a given model. Models ranging from simple one step reactions to highly complex reaction schemes are easily entered into the software.

In addition, concentration profiles and calculated spectra for each reaction component provide clear evidence and support for the presence of short lived reaction intermediates.