Isothermal Titration Calorimetry (ITC)

Isothermal titration calorimetry quantifies binding affinity (Kd), stoichiometry, and thermodynamic parameters such as enthalpy and entropy. ITC is particularly effective for measuring the binding of small molecules to biomolecules. However, ITC can be demanding in terms of material requirements. We have three ITC instruments:

• PEAQ-ITC
  PEAQ-ITC is our most modern and user-friendly ITC instrument, featuring small cell and syringe volumes, automated cleaning procedures, and highly intuitive software.

• Microcal iTC200
  The ITC200 has a small cell volume, requiring less material than the VP-ITC but needing slightly higher sample concentrations.

• VP-ITC
  The VP-ITC has a larger cell volume, making it suitable for samples with limited solubility.

Surface Plasmon Resonance (SPR)

• Biacore T100
  Surface plasmon resonance measures the binding and dissociation rates of biomolecules attached to a chip, enabling determination of binding affinity. Unlike other interaction analysis instruments, SPR also provides rate constants (kinetics). SPR is best suited for interactions between macromolecules, and in some cases, small molecules.

Grating-Coupled Interferometry (GCI)

• Creoptix WAVEsystem Delta
  Similar to SPR, GCI measures binding and kinetic parameters of biomolecules on a chip. The Creoptix system is modern, with clog-free microfluidics and higher sensitivity than the Biacore T100. Additionally, it offers waveRAPID, a quick and convenient alternative to multi-cycle kinetics.

Microscale Thermophoresis (MST)

• Nanotemper NT.115 (Blue-Red and Blue-Green)
  MST measures the migration of fluorescently labeled molecules in a thermal gradient. The migration shifts upon ligand binding, allowing affinity determination by titrating the ligand. MST requires one interaction component to be fluorescently labeled and can operate in the presence of detergents, making it suitable for many membrane proteins.

Fluorescence

In certain systems, titration may be monitored using fluorescence. The Nanotemper Panta can track titration based on the spectral shift of tryptophan fluorescence, which works best when a tryptophan residue is near the binding site. Additionally, the multimode plate reader includes a fluorescence polarization module, which is effective for small, fluorescently labeled molecules, such as peptides.

Differential Scanning Fluorimetry (DSF) / Dynamic Light Scattering (DLS)

• Nanotemper Prometheus Panta
  The Prometheus Panta is a state-of-the-art instrument for nanoscale differential scanning fluorimetry (DSF) and dynamic light scattering (DLS). Thermal stability is assessed by monitoring the spectral shift of tryptophan during protein unfolding, providing a melting temperature. The Panta processes 48 samples in parallel, making it well-suited for moderate-throughput screening. Common applications include protein formulation under stable conditions, mutant comparison, and ligand screening. The DLS module also measures particle size and homogeneity at a static temperature or during thermal unfolding.

• Nanotemper Tycho NT.6
  The Tycho NT.6 is a rapid alternative to the Panta, designed for quick assessment of sample quality between purification or treatment steps via thermal unfolding. It can process six capillaries simultaneously with a heating rate of 30 °C/min, yielding results in just 3 minutes. The resulting transition curves provide relative comparisons across samples, though they do not represent the true melting point of the protein due to the fast temperature ramp.

Mass Photometry

• Refeyn MPTwo
  The Refeyn MPTwo mass photometry instrument measures particle sizes in solution at the single-molecule level, making it ideal for analyzing heterogeneous mixtures of complexes. With a lower detection limit of 30 kDa, it is suited for samples at concentrations around 10 nM.

Dynamic Light Scattering (DLS) / Static Light Scattering (SLS)

• Malvern Zetasizer µV
  The Zetasizer µV is a cuvette-based system tailored for protein analysis, using dynamic light scattering (DLS) to measure particle size and static light scattering (SLS) to determine molecular weight.

• Nanotemper Prometheus Panta
  The Panta includes a DLS module that measures particle size and homogeneity either at a static temperature or during thermal unfolding, requiring only approximately 10 µl of sample loaded into a glass microcapillary.

Liquid Scintillation Counter

• Perkin-Elmer Tri-Carb 4910 TR
  The liquid scintillation counter detects radioactivity from various isotopes commonly used in biochemical assays, including ^3H and ^32P. All work with radioactive isotopes must adhere to local safety regulations.

Multimode Plate Reader

• Molecular Devices SpectraMax i3
  The multimode plate reader supports a range of optical measurements for biochemical assays, including absorbance, luminescence, fluorescence, FRET, and fluorescence polarization. Its plate format makes it ideal for high-throughput experiments.

Microvolume Spectrophotometer / Cuvette Spectrophotometer / Microtube Fluorimeter

• DeNovix FX+
  This versatile instrument offers 1 µL UV-Vis, cuvette UV-Vis, and microtube fluorescence (for e.g. Qubit) capabilities. It is available without booking and free of charge.

Sample Preparation Instruments
All sample preparation instruments are available for use without booking and free of charge.

Centrifuge

• Eppendorf Centrifuge 5420
  A tabletop centrifuge designed for microtubes (1.5 and 2 ml) with a maximum speed of 20,000 rcf.

Microvolume Spectrophotometer / Cuvette Spectrophotometer / Microtube Fluorimeter

• DeNovix FX+
  This fully specced instrument offers 1 µL UV-Vis (nanodropesque), cuvette UV-Vis, and microtube fluorescence capabilities. It supports measurements of protein and RNA/DNA concentrations, colorimetric assays, and fluorescence-based kits.