Observing Real Time Protein Aggregation Using Dynamic Light Scattering

By AZoNano

Table of Contents

Introduction
Experiment and Results
Conclusion
About Avid Nano

Introduction

Dynamic light scattering (DLS) is a common technique utilized in the determination of size and distribution of molecules, particles and their aggregates in different solvent conditions.

In a recent case study, DLS was used to explore a molecule’s spontaneous self-association in a solution. The results from the study demonstrated the speed and power of the DLS technique. DLS facilitates real-time observation of dynamic processes thanks to the 'ensemble' measurement technique and short acquisition times.

Experiment and Results

In the study, the initial measurement of a peptide compound in solution using the W130i DLS system showed a mixture containing monomers and aggregates. The sample was centrifuged at a rate of 10,000 rpm for a period of 10 minutes to reduce the aggregate content.

The re-analysis of an aliquot showed no aggregate peak, but a single peak of narrow size distribution as depicted in Figure 1.

Figure 1. 0 min - after centrifuge

After four minutes, the second measurement was performed, revealing a small secondary peak as shown in Figure 2.

Figure 2. 4 min - 2nd peak visible

Subsequent measurements taken at later time intervals highlighted an increasing light scattering signal from the aggregate content as illustrated in Figure 3. However, the size of the monomer peak remained the same.

Figure 3. 20 min - aggregates forming

The process conducted for 45 minutes until the restoration of the original monomer/aggregate equilibrium as demonstrated in Figure 4.

Figure 4. 45 min - equilibrium restored

Conclusion

Since the DLS technique is able to measure non-invasively and rapidly, it makes it easy to observe dynamic processes with high sensitivity.

About Avid Nano

Avid Nano produce the most exciting and innovative new dynamic light scattering products. Avid Nano pursue the highest levels of performance, know-how, technology, convenience and reliability for all our products, used in laboratory applications requiring fast, accurate DLS measurements in the nano-metre size range.

The W130i dynamic light scattering system is a breakthrough, high sensitivity instrument for size and molecular weight measurement of proteins, bio-molecules and sub-micron particles. The W130i combines ultimate measurement performance with an economical benchtop footprint, rugged durability and supreme user convenience. It's extraordinarily compact dimensions are the result of miniaturized 'diamond geometry' S.A.B.Re fibre optic technology.

This information has been sourced, reviewed and adapted from materials provided by Avid Nano.

For more information on this source, please visit Avid Nano.

Date Added: Feb 12, 2013 | Updated: Jun 11, 2013
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