Biophysical characterization

Sample characterization is a fundamental part of research that should not be overlooked. 

The basic characteristics of the protein sample (identity, purity, homogeneity, stability) should always be checked before subsequent analysis for interaction or structure determination. By doing so, it ensures higher reproducibility of results and improves the quality of the experiments. Accessing a combination of various methods unlocks detailed analysis of the sample over a short time and eventually spares precious resources for downstream measurements.

Homogeneity can be analysed via dynamic light scattering (determination of hydrodynamic radius, presence of aggregates), and SEC-MALS (accurate mass determination, and purity).

Thermal and/or chemical stability can be monitored using differential scanning fluorimetry (intrinsic fluorescence), or circular dichroism (conformational changes, secondary structure determination). Stability can be improved by changing buffer composition. We offer multiple buffer screens on site.

Purity of samples can be checked with accurate mass determination using SEC-MALS.

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Circular dichroism: Chirascan Plus

CD is used to determine the folding state and secondary structure of proteins. CD is the difference in absorption of left-handed and right-handed circularly polarized light and can be observed in chiral chromophores. VBCF ProTech has a Chirascan Plus spectrophotometer.

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Dynamic light scattering: DynaPro Plate Reader II

DLS measures the time-dependent fluctuations in scattered light. These fluctuations are directly related to the rate of diffusion of the molecule through the solvent, and can be used to measure hydrodynamic radius (Rh) of the particles in solution. ​​​​​​VBCF ProTech has a DynaPro Plate Reader II.

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Differential Scanning Fluorimetry: Prometheus NT.48

DSF measures protein unfolding by monitoring changes in fluorescence as a function of temperature. NanoDSF measures changes in intrinsic protein fluorescence as proteins unfold. VBCF ProTech has a Prometheus NT.48 fitted with aggregation optics.

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SEC-MALS: OmniSEC

SEC-MALS is used to accurately measure weight-averaged masses (Mw) of macromolecules in solution by measuring the intensity of scattered light of a sample as it elutes from an SEC column. VBCF ProTech has a OmniSEC system for service request only.

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​UV-Vis Spectrometer: DS-11+

Easy quantitation of the amount of protein or nucleic acids. It is highly recommended to check for concentration prior any biophysical experiment. VBCF ProTech has a DS-11+ Spectrophotometer.