Hydrodynamic Size Measurements of 0.1 mg/ml Protein Solutions by Dynamic Light Scattering

By AZoNano

Table of Contents

Introduction
Lysozyme Sample Preparation and DLS Measurement
Results of Hydrodynamic Size Measurement
Conclusion
About Avid Nano

Introduction

The W130i dynamic light scattering system and i-Size software from Avid Nano rapidly and accurately measures hydrodynamic size of sub-micron particles and molecules. Cleanliness, care and patience are the basic rules required to take measurements of trace amounts of weakly scattering protein molecules.

Following these basic rules, the W130i dynamic light scattering (DLS) system and i-Size software can provide measurement of lysozyme (14kDa monomer) down to 0.1 mg/ml.

Lysozyme Sample Preparation and DLS Measurement

A solution of lysozyme powder in filtered PBS was prepared at a concentration of 0.1 mg/ml and allowed to settle for one hour. 12 µl of the prepared solution was passed through a 0.02 µm pore size filter, directly into a thoroughly cleaned quartz glass measurement cuvette. The prepared sample was then placed in the temperature controlled cell holder of the  W130i DLS system ready for analysis.

Results of Hydrodynamic Size Measurement

Figure 1. Correlation functions for DLS measurements of 0.1mg/ml Lysozyme solutions

Figure 2. Hydrodynamic diameter distribution of lysozyme solution

The correlation functions and size distributions obtained as shown in the above graphs reported by i-Size 2.0 software represent a single peak of radius of 2.0 nm, which is suitable for lysozyme.

Conclusion

It is a challenge to take measurements at the limits of dynamic light scattering sensitivity. However, the robust W130i DLS system and i-Size software are capable to provide reliable results from the most difficult conditions.

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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