Hinderberger Group - Instruments

W-Band
Bruker/Cryogenics

Our high filed pulsed EPR spectrometer running at W-band regime (3.4T/ 94GHz). The W-band uses a Bruker E680 console, a TeraFlex microwave bridge along with an oxford IPS-120 power supply. A cryogen free magnet (Cryogenics 2017) with an integrated VTI (Virtual Temperature insert) produces magnetic fields up to 6T and enables operations between 2K and room temperature. Magnet operation is controlled by Cryogenic software and as of the Bruker console, we use Xepr. The setup is equipped with an ENDOR cylindrical resonator (EN600-1021H, Bruker).

X-Band Pulse EPR Spectrometer
Bruker

The Elexsys E580 Bruker spectrometer, operating at X-band range (0.3T /9.7GHz) at both cw and pulse modes. We use a closed cycle cryostat (ARS- 4WH, www.arscryo.com) to supply Helium. We got a digital upgrade of the system (Bruker Biospin, 2019) on microwave bridge controller, Hall field controller, signal processing unit (SPU), SpecJet-III (0.5 ns of transient resoloution) and PatternJet-II Pulse Programmer.

A second MW source (Magnettech GmbH) is provided for electron double resonance experiments. The X-band frequency is amplified either by a 1kW Traveling Wave Tube (TWT-Applied system Engineering, USA) or a 300W-solid state amplifier (Bruker Biospin, 2022). An arbitrary waveform generator (SpinJet AWG, Bruker, sampling rate of 1.6 GS/s and 0.625 ns time resolution) enables us to use shaped pulses (Bruker Biospin, 2022).

The X-Band is also equipped with an RF power amplifier (ENI 3200L, 200W, 250KHz-150MHz), DICE pulsed ENDOR unit (E560D-P-RF).

e setup has two flexline split-ring resonators ER4118X–MS3 (pulsed EPR) and a flexline probehead ER4118X–MD4 for ENDOR measurements.

Q-Band
Bruker

The EMX-plus Q- spectrometer from Bruker, operating at Q-band range (1.2T /34GHz)in the CW-mode. We use a closed cycle croyostat (ARS- 4WH) along with a SOMITOMO-F70 compressor and Mercury iTC (Oxford Instruments) to reach and control temperature ranges between 5 and 300K. Qunitina is equipped with an ER5106QT/W cylindrical probehead.

MS5000
Freiberg Instruments/Bruker

The benchtop electron spin resonance (EPR) spectrometer measures  paramagnetic species at X-Band frequencies in continuous-wave (CW) mode.  Measurements of solid or liquid samples with a volume of 12-100 µL can  be performed at temperatures from the boiling point of liquid nitrogen  up to 200 °C. EPR spectroscopy is suitable for the investigation of  (bio)chemical systems with strongly localized spin density and their  interaction with the environment. It provides information about  structure and dynamics of the system of interest.

Multi-Wavelength Fiber Coupled LEDs
Prizmatix

The fiber-coupled high power UV, Blue, Green, Red and NIR LED multi  wavelength light source modules are effective replacements of lasers  and lamps in many applications. We use them for photochemical reactions  and irradiation of samples inside the MS5000 EPR spectrometer to  investigate photochemical radical formation or decay.

Miniscope MS400
Magnettech

Both spectrometers are used for research (spin probing, spin trapping and spin counting), as well as training. These spectrometers can be operated in a temperature range from -180°C up to 200°C. They are equipped with rectangular cavity TE102. Maximum available field range is up to 6500G. Their sensitivity is about 10⁸-10⁹ spins/G. Nitrogen temperature measurements are possible using liquid nitrogen Dewar.

Litesizer
Anton Paar

The Litesizer 500 is used to characterize particles in dispersions. Static light scattering at 90° determines the molecular weight, dynamic light scattering at 15°, 90° and 175° is used to calculate the particle size, and with electrophoretic light scattering (cmPALS) the zeta potential is investigated. Furthermore, the transmissions and refractive indices of solutions can be measured.

Fluoromax-2
ISA/ Horiba

The FS5 fluorescence spectrometer is a highly sensitive and versatile measurement system for the optical characterization of fluorescent and phosphorescent materials. The system can be used to determine fluorescence and excitation spectra, absorption spectra, and photoluminescence quantum yields. Using the Time-Correlated Single Photon Counting (TCSPC) module, it is also possible to measure fluorescence lifetimes in the pico- to microsecond range and to perform time-resolved luminescence measurements with high temporal resolution.
The FS5 is suitable for investigating electronic transitions, photophysical processes, and energy transfer mechanisms such as Förster resonance energy transfer (FRET). Furthermore, reaction and binding processes can be monitored using fluorescence spectroscopy, and the release of dye from lipid vesicles can be quantified.

IRRAS
Bruker Invenio mit A511 Reflexionsmodul

We investigate thin layers at the water-air interface using infrared reflection-absorption spectroscopy (IRRAS), which we coupled with a Langmuir monolayer trough setup. This allows us to collect spectroscopic information about the molecules at the surface alongside the thermodynamic parameters of the film. We can track lipid phase transitions as well as protein adsorption and secondary structure changes. Additionally, by varying the angle of incidence and the polarization of the IR beam, we can determine the orientation of molecules at the surface and the thickness of the adsorbed layer.

IR Tensor with Diamnod ATR
Bruker

IR Vertex with BioATR Cell
Bruker

Monolith NT.115r
NanoTemper

With the Monolith NT 115r from NanoTemper, the method of microscale thermophoresis can be used to analyze the binding between molecules, e.g. enzymes and ligands, through the measurement of fluorescence intensity differences. For that, capillaries with a varying amount of target molecule and a constant amount of green or blue fluorescent binding partner get radiated with an IR-Laser to generate a temperature gradient. Because of the “Soret-Effekt”, bound and unbound molecules diffuse away from the “warm” detection region with different velocities, resulting in a different decrease of the fluorescence intensity, depending on the ratio of bound to unbound molecules. A graphic plot of the normed intensity against the varying concentration of one binding partner enables the fit of a binding curve and the precise determination of dissociation constants (K_D-values) in the micro- to nanomolar range.

Compression Film Balance

In a Teflon trough with moveable barriers, the surface pressure at the water-air interface is measured by a Wilhelmy plate. A surface-active substance, like phospholipids dissolved in chloroform or polymers can  be spread unto an aqueous subphase. Chloroform is left to evaporate and  the molecules to equilibrate before compressing the molecules with the barriers. Thereby the available molecular surface area is reduced  leading to an increase in surface pressure depending on the phase of the molecule. An area isotherm is measured giving information about phase  transitions of the molecules in a monolayer at the water-air interface.

Adsorption Film Balance

A Wilhemly plate measures the surface pressure at the water-air  interface. Phospholipids or other surface active molecules can be  spread unto an aqueous subphase in a Teflon trough. Using a syringe,  molecules or proteins can be injected into this subphase directly  through an injection hole in the trough or by injection through or unto  the surface from above. This allows measurement of the surface pressure  increase and gives information of for example of protein lipid-monolayer interaction.

Fluoreszenzmicroscope

The Axio Scope A1 Vario epifluorescence microscope (Carl Zeiss MicroImaging, Jena, Germany) is mounted above a compression film Balance and thus allows recordings of lipid monolayers at the air-water interface. The system is equipped with an excitation filter, a beam splitting unit and a HXP 120 C mercury lamp. Images can be taken with an EMCCD camera (ImageEM C9100-13, Hamatsu, Herrsching, Germany).

Film Balance G1
Kibron

The Film Balance is an instrument designed to study the  molecular films at the air–liquid interface. It enables precise  measurements of surface pressure and the characterization of Langmuir  monolayers, providing valuable information on molecular packing, film  stability, phase behavior, and intermolecular interactions. The system  is widely used in research on lipids, proteins, polymers, surfactants,  nanoparticles, and other interfacial materials across biophysics,  surface chemistry, and materials science. It operated with a surface  potential probe an and a Brewster angle microscope. Barriers can be  oscillated to measure dilatational surface rheology and Films can be  transferred to solid supports by a integrated filmlif

Dalta Pi 4
Kibron

The Kibron Delta Pi4 film balance is used to study monolayers at the air-water interface and enables the characterization of amphiphilic molecules, lipids, and surfactants. Under controlled conditions, the integration and interactions of proteins or polymers in monolayers can be characterized. A particular advantage of the Kibron Delta Pi4 system is its low sample requirement: measurements require only very small sample volumes, allowing experiments with valuable or limited-availability substances to be conducted efficiently. Furthermore, the system enables up to four measurements to be performed simultaneously under nearly identical conditions. This increases sample throughput and improves the reproducibility of experimental data.

Tensiometer
DropShape

The drop shape tensiometer enables surface tension measurements based on the shape analysis of a drop or bubble. Therewith, molecular adsorption processes at interfaces can be studied. Here, surface tension and gravity are competing: the lower the surface tension, the more elongated the drop, whereas high surface tension results in a more spherical drop. The analysis is based on the Young-Laplace equation. Additionally, sinusoidal oscillations of the drop area can be performed to investigate the rheological properties of the interface. This is particularly useful for proteins, as it allows insights regarding aggregation and cross-linking at the surface.

Refractometer
Anton Paar

The Anton Paar Abbemat 450 heavy-duty refractometer enables refractive index and concentration measurements to be made with an accuracy of ± 0.0001 nD. Due to the particularly robust design, aggressive chemicals can also be measured. The measurable temperature range is from 5-125° C. Due to the small sample well, only 200 µl sample volume is required for a measurement. The device can be controlled both via a digital control unit and via a computer.

Rheometer
Anton Paar

The Rheometer Physika MCR 301 from Anton Paar is equipped with different measuring systems. We have Coneplate (CP) and PlatePlate (PP) measuring systems of various sizes, so samples with small amounts of approx. 180-200 µl or sample volumes of up to 2 ml can be measured. The rheometer enables the measurement of viscosity and viscoelastic behavior of liquid or solid samples.

Rheometer MCR 302 AntonPaar
Anton Paar

The model MCR 302e can be equipped with different measuring systems. We have measuring cones (CP) and
plates (PP) with diameters of 25 or 50 mm. These allow analysis of samples with approx. 200 μL or up to 2 mL.
Oscillation and rotation measurements can be performed with a torque of 0.5 nMm to 230 mNm and over a wide
range of temperatures.

TRPS (qNano)
IZON

Tunable Resistive Pulse Sensing (TRPS) measures individual particles size, concentration and zeta potential with incredibly high precision and accuracy. TRPS is more accurate than commonly used light scattering techniques that provide bulk estimates. The qNano Gold can be used for Particles that exeed 30 nm. The concentration of particles in the fluid as a number of particles per unit volume of fluid, across a specified detectable particle size range. An accurate size distribution of these particles plotted as a histogram of concentration v particle diameter (or volume). TRPS is the technology that delivers these fundamental requirements, and in addition can measure the surface charge of individual nanoparticles.

Äkta Pure
Cytiva

The ÄKTA^TM system is a Fast Protein Liquid Chromatography (FPLC) system which can be used to purify biomolecules such as proteins, peptides, and antibodies. Its applications for example include solvent exchange and desalting, as well as the separation of different proteins. The ÄKTA^TM can be used to perform affinity, size-exclusion, or ion-exchange chromatography.

VP-ITC
MicroCalorimeter

Isothermal titration calorimetry quantifies heats of reaction or binding. With the help of a dosing syringe, one reactant/ binding partner is titrated into the measurement cell containing the other reactant/binding partner. The produced or consumed heat is recorded as it is compensated with respect to a reference cell to keep the process isothermic.

DSC
Microcal vp-DSC

The sensitive microcalorimeter for liquid samples enable us to measure phase transition temperatures and transition enthalpies of lipid membranes, as well as denaturation temperatures of proteins. We use this method to examine the influence of membrane-binding molecules on the phase state, as well as to study lipid mixing and demixing within the membrane.

LISO

The "Lipid State Observer" is a fluorescence method based on the fluorophore laurdan, which emits different wavelengths based on the polarity of its environment (e.g. a lipid membrane). This allows for the determination of a lipid phase transition temperature, as well as the characterization of the insertion of peptides or similar substances. Compared to similar methods like DSC of dilute aqueous solutions, the measurement at negative temperatures is possible and the amount of sample is reduced.

Osmometer
Knauer

An osmometer is used to determine the osmolarity of liquids by measuring the
concentration of dissolved particles using the freezing-point-depression method.
Determining osmolarity is particularly important when different buffer solutions are
separated from one another by a semipermeable membrane. If there are differences in the
osmolality of the buffers, water exchange (osmosis) occurs between the solutions. This can
lead to undesirable changes in concentration and, in the worst case, to damage or
destruction of the membrane.