Application noteRapid quality control of commercially available antibodies by MDS for acceptance testing
Size presents a simple metric to assess quality as an indicator of aggregation and degradation. Here MDS on the Fluidity One and SEC analysis are both used to check 6 commercially available antibodies. Both techniques sucessfully identify problem samples, but MDS does so with 80% less time and 90% less sample.
Application noteDetermination of lipid protein binding stoichiometry using Microfluidic Diffusional Sizing
Here we assess the stoichiometry of α-synuclein binding to lipid vesicles by microfluidic diffusional sizing (MDS) on the Fluidity One and Circular Dichroism (CD). We find that the results obtained are consistent between the two techniques, but that MDS presents advantages in both speed and simplicity.
Application noteDetermination of KD of aptamer protein interactions by microfluidic diffusional sizing
Here the Fluidity One-W is used to experimentally determine the KD of two protein aptamer interactions, with results in good agreement with literature values. Importantly the technique required no calibration, complex setup or specialist sample preparation. Furthermore, the interaction is assessed without immobilising or altering either molecule beyond the addition of a standard fluorescent label.
Application noteQuantitation of low Tryptophan and Tyrosine peptides using the Fluidity One
UV absorbance is commonly used as a fast method for protein and peptide quantitation, however samples must contain tryptophan (Trp) or tyrosine (Tyr) residues to be detected. Here we demonstrate the ability of the Fluidity One to assess the concentration of a range of samples which have low or no Trp and Tyr content.
Application noteProtein Size as an Indication of Structure
Molecular weight (Mw) is a commonly used, and for many scientists a readily understood, parameter to describe the size of a protein or complex. Here we show how hydrodynamic radius (Rh) can be used in combination with Mw to provide insights into the shape and structure of proteins and illustrate how Mw alone may not always provide a complete picture.
Application noteOligomerization of Interleukin-2
A commercially available human interleukin-2 is assessed by microfluidic diffusional sizing on the Fluidity One across a dilution series. The hydrodynamic radius is observed to increase with increasing concentration, in a way which suggests a monomer-trimer equilibrium with positive cooperativity is established.
Application noteInterleukin-2 stability in changing buffer and temperature conditions
The stability of interleukin-2 in different buffers and storage temperatures is evaluated using the Fluidity One. We find that IL-2 forms aggregates within 24 hours in some buffers, and that the Fluidity One provides a simple means to evaluate the stability of proteins across different conditions.
Application noteA comparison of Microfluidic Diffusional Sizing with Dynamic Light Scattering and Taylor Dispersion Analysis
The established technologies of Dynamic Light Scattering (DLS) and Taylor Dispersion Analysis (TDA) are compared to Microfluidic Diffusional Sizing (MDS) for sizing proteins of varying molecular weights and at varying concentrations. We show that MDS offers comparable sizing of proteins over a range of sizes, and can provide consistent sizing to lower concentrations than the other techniques.
Application noteDetecting insulin oligomerization using microfluidic diffusional sizing
Insulin monomers self-assemble into hexamers, which is known to affect its level of uptake in the human body. Here we show that Microfluidic Diffusional Sizing (MDS) can be used to detect these changes.