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Dynamic Light Scattering

Dynamic light scattering (DLS), sometimes referred to as Quasi-Elastic Light Scattering (QELS), is a non-invasive, well-established technique for measuring the size and size distribution of molecules and particles typically in the submicron region, and with the latest technology lower than 1nm. Dynamic light scattering (DLS) is often used to determine the size of particles in suspension and or polymers in a solution. We cover off a number of dynamic light scattering (DLS) articles here in our ever growing dynamic light scattering (DLS) blog category.

Customer experience, Dynamic Light Scattering, Meet the Experts, Particle size, Zetasizer »

[20 Jun 2017 | ]

Three methods to verify dynamic light scattering systems
If you are a meticulous researcher you may want to test your new Zetasizer. Is it really providing the correct size? One of the advantages of dynamic light scattering is that there are no tweakable adjustments, it is all physics: laser wave length, scattering angle, refractive index of the dispersant are all known in advance and are given parameters for the optical setup and sample. Nevertheless, it is a good idea to check and verify the performance of the system. One of the …

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Customer experience, Dynamic Light Scattering, Electrophoretic light scattering, Molecular size, Particle size, Zeta potential, Zetasizer »

[25 May 2017 | ]

A challenge to all new Zetasizers!
 
The Zetasizer is so simple to use that the majority of Zetasizer (user)s just “dive in” and find out how to operate the system.
By design it is (almost) indestructable, so what can go wrong? Not much – nevertheless, you might be able to get even more use and benefit from your system with a little preparation.
 
Free eLearning video – really!
If you are relatively new to the Zetasizer then take a look at our free eLearning introductory course. It was meant as a teaser for the …

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Dynamic Light Scattering, Meet the Experts, Taylor Dispersion Analysis, Tech Talk, Viscosizer TD, Zetasizer »

[18 May 2017 | ]

Matt McGann and I will be representing Malvern at the upcoming annual UD Biophysical Characterization Workshop, sponsored by CBST (Center for Biomanufacturing Science & Technology), BITC (Biomolecular Interaction Technologies Center), and the University of Delaware, on June 6, 2017, hosted by Professor Christopher Roberts.
This year’s workshop will consist of three days of short courses and small-group demonstrations of the principles and commercial technologies for characterization of protein solutions and related colloidal systems, focusing specifically on static and dynamic light scattering, electrophoresis (DLS, ELS), and Taylor Dispersion Analysis (TDA).
Matt has been …

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Customer experience, Dynamic Light Scattering, Molecular size, Particle size, Zeta potential, Zetasizer »

[4 May 2017 | ]

3 stumbling blocks for Report Designer (Zetasizer) – the rule of two
The three most common holdups encountered in the report designer feature are listed here.
Not everyone delves into the depth of the Zetasizer software, but of those who do want to take advantage of the report customization features in the ‘report designer’ nearly everyone runs into at least one of these three common mistakes:

1. Folder locations – there are two!
The Zetasizer software is typically installed in a (hidden) Windows directory like  C:\Program Files\Malvern Instruments\Zetasizer Software and that’s good. However, if …

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Corporate, Customer experience, Dynamic Light Scattering, Inside Malvern, Zetasizer »

[25 Apr 2017 | ]

Exposition at scientific meetings:
How useful are they and can they help me to get a job?
A brief insight from the ACS meeting
If you follow my writings, you’d probably expect more detail about Dynamic Light Scattering (DLS)… However, today I’d like to report on a recent conference we went to, the national meeting of the American Chemical Society, otherwise known as ACS. It is the world’s largest scientific society by number with close to 160k members.  There were over 17k registrants at the San Francisco meeting earlier this month, quite a turnout. With the constant …

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Dynamic Light Scattering, Electrophoretic light scattering, Meet the Experts, Static Light Scattering, Zeta potential, Zetasizer »

[16 Mar 2017 | ]

Recently, I hosted a webinar which discussed what surface zeta potential is and how it can be measured. The webinar attracted huge interest and it was a pleasure to see so many people attending and asking some excellent questions. In fact, there were so many questions asked, that we ran out of time at the end of the webinar and had to answer many of them via e-mail. Some of these are listed below.
The webinar discussed the zeta potential of solid, planar surfaces (rather than colloidal dispersions or molecular solutions) …

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Dynamic Light Scattering, Molecular size, Particle concentration, Particle size, Protein Aggregation, Tech Talk, Zetasizer »

[7 Mar 2017 | ]

How can I use DLS for sample xyz?
What sample concentration / refractive index is needed for reliable DLS size measurements?

Has it been done before?
In Dynamic Light Scattering (DLS) intensity fluctuations in the sample are analyzed to obtain size information on the sample. The technique is applicable to a wide size range from sub-nanometer up to a few microns. In order to obtain a meaningful result, a minimum scattering signal strength must be present. Malvern’s Zetasizer Nano software contains a calculator to help estimate the required minimum concentration.
If anyone else has …

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Binding affinity and Kd, Differential Scanning Calorimetry, Dynamic Light Scattering, Français, Gel permeation chromatography, Image Analysis, Isothermal Titration Calorimetry, Laser Diffraction, Meet the Experts, Molecular size, Nanoparticle Tracking Analysis, Particle concentration, Particle size, Rheological and Viscosity, Rheometry - Rotational, Size Exclusion Chromatography, Static Light Scattering, Zeta potential »

[21 Feb 2017 | ]

Afin de vous apporter un support concret pour utiliser votre système de façon optimale, finaliser vos bonnes pratiques de laboratoire et répondre à vos besoins spécifiques, Malvern organise des formations sur site ou en sessions dans nos 3 agences françaises (Orsay, Lyon et Toulouse).
Voici les dates de toutes les sessions programmées pour 2017 :
CARACTERISATION DES PARTICULES PAR DIFFRACTION LASER
Objectifs : Perfectionner les méthodes de caractérisation des particules en voie sèche et liquide, définir les bonnes pratiques de laboratoire et s’adapter aux besoins spécifiques de chaque installation. Comprendre le principe physique …

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Dynamic Light Scattering, Gel permeation chromatography, Malvern Events, Meet the Experts, Nanoparticle Tracking Analysis, Size Exclusion Chromatography, Zeta potential »

[26 Jan 2017 | ]

We will be attending Pittcon 2017 in Chicago, Illinois March 5th – 9th and once again we are pleased to feature a number of our recognized characterization experts who will be presenting a variety of short courses throughout the week.
Time is running out, so don’t miss out on the early bird deadline for discounted admission which ends on February 18th.
Below is a listing of our available short course offerings.
We look forward to seeing you in Chicago at one of our short courses and our Booth #2416.
Sunday, March 5, 2017 – 8:30 AM
Light Scattering …

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Dynamic Light Scattering, Particle size, Zetasizer »

[23 Jan 2017 | ]

Over the years one of the frequently asked questions that stands out in the data analysis of dynamic light scattering results is the issue about which size one should report.
 
 
 
Here is an example of just such an email I received this month:
“We have several data sets with low PDI (<0.1), single exponential decay, low cumulant fit error(~10^(-4)).  The intensity-distribution size and the cumulant fit size are similar.  But the number-distribution size (d=33 nm)and size obtained by cumulant fit(d=47 nm) are very different.  In this case, should we trust the number-distribution size …

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Dynamic Light Scattering, Molecular size, Molecular structure, Particle size, Tech Talk, Zetasizer »

[27 Dec 2016 | ]

How to measure it with DLS?
What virus concentration is needed for reliable DLS size measurements?
 
What is a virus?
In cell biology, a virus is a self assembly of organic molecules (mainly proteins) in the size range 20 nm – 300 nm (diameter). Viruses hold great interest for human gene therapy researchers, and the AAV-2  virus shown to the left is an example.
How to size a virus in solution?

One of the techniques available to size viruses (as well as other biological nanoparticles) is Dynamic Light Scattering (DLS), where intensity fluctuations in a small …

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Customer experience, Differential Scanning Calorimetry, Dynamic Light Scattering, Français, Isothermal Titration Calorimetry, Meet the Experts, Nanoparticle Tracking Analysis, Tech Talk »

[14 Dec 2016 | ]

Journée d’information APGI/MALVERN – “Nouvelles méthodes de caractérisations des biomolécules”

Mercredi 11 janvier 2017 au CNAM
Co-organisé avec APGI et le CNAM
Avec le développement rapide de biomolécules dans les nouvelles thérapies, des techniques de caractérisation innovantes se développent en parallèle des techniques classiques (comme par exemple la chromatographie d’exclusion couplées à de la triple ou tetra détection, ou la technique NTA, très adaptée à la mesure des exosomes, des particules subvisibles et tout autre type de contaminant, etc).
C’est pourquoi l’APGI (Association de Pharmacie Galénique Industrielle) et Malvern vous invitent à une journée …

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Dynamic Light Scattering, Français, Laser Diffraction, Malvern Events, Meet the Experts, Nanosight, Particle size, Static Light Scattering, Zetasizer »

[23 Nov 2016 | ]

Les 20èmes rencontres organisées à Rennes auront lieu du 28 au 30 novembre avec la collaboration l’Institut des Sciences Chimiques de Rennes et la plateforme ScanMat. La directrice de cette plateforme, Maryline Guilloux-Viry, nous fera l’honneur d’accueillir les participants et de présenter les moyens et compétences disponibles au sein de la fédération des 5 plateformes constituant ScanMat (Microscopies électroniques, Analyses structurales et élémentaire, Synthèse et mise en forme, Spectroscopies et Microspectroscopies optiques).
Les nanoparticules seront au cœur de ces rencontres avec une évocation des nouvelles réglementations de REACH qui seront en vigueur …

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Corporate, Dynamic Light Scattering, »

[17 Nov 2016 | ]

JASIS (Japan Analytical Scientific Instruments Show), one of the largest exhibitions in Asia for analytical and scientific instruments, took place recently at the Makuhari Messe in Chiba, Japan.
Malvern Instruments received some great news at this meeting, which we are delighted to share with you: we won the “Analytical and Scientific Instrument Heritage Certification” award for the High Speed Digital Correlator and Probability Analyser System Type K7023.
The aim of this award is to communicate information to the Japanese people about valuable analytical technologies and scientific instruments that contribute to the country’s life, economy, education …

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Dynamic Light Scattering, Molecular size, Protein Aggregation, Tech Talk, Zetasizer »

[1 Nov 2016 | ]

α-synuclein promotes vesicle assembly – when size can support theory
 

What is a vesicle?
In cell biology, a vesicle is an (often spherical) assembly of amphiphilic molecules (usually proteins and phospholipids), and is typically sized between 30 nm – 100 nm in diameter. Vesicles are often classified by the type of interaction they are involved with. For extracellular vesicles (or exosomes), this is usually intercellular signal transmission. A particular example of exosomes is synaptic vesicles, which transmit signals between neurons (average size: 40 nm).
In a paper entitled “Structural basis of synaptic vesicle assembly promoted …

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Customer experience, Dynamic Light Scattering, Electrophoretic light scattering, Molecular size, Molecular weight, Particle size, Zeta potential, Zetasizer »

[20 Oct 2016 | ]

How can I save paper and print a Zetasizer report as a PDF?
 
Why print?
The Zetasizer software includes several popular report options. The most frequently used of these is probably the Intensity PSD (M), which gives a compact overview of the results. It lists the z-average and up to three peaks by intensity with their respective mean size, the area under the peak in % intensity and the standard deviation of the peak. In addition, several relevant sample identifiers and measurement conditions, like the sample name,  file name, refractive index of …

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Dynamic Light Scattering, Electrophoretic light scattering, Meet the Experts, Particle size, Protein Aggregation, Zeta potential, Zetasizer »

[11 Oct 2016 | ]

Adjuvants for vaccination – How size and zeta may be relevant
 
What is an adjuvant?
Adjuvants are substances which are added to medicines to trigger and enhance an immune response to an antigen. In the USA, the most commonly-used adjuvant is alum, and many vaccines in use today contain some aluminum components to help the vaccine work better. While the exact mechanisms of how adjuvants work is unclear to some extent, a typical adjuvant component is much larger than the antigen or antibody itself, often around 100 nm in radius.
In a paper entitled …

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Dynamic Light Scattering, Particle size, Tech Talk, Zetasizer »

[20 Sep 2016 | ]

Washing dishes with DLS

How does dish washing work?
Surfactants have seemingly magical properties: combine greasy plates with dish washing liquid and hot water and the dishes become squeaky clean again.
So, how does that actually work?
Detergents are often amphiphilic molecules which means that have both a hydrophilic and a hydrophobic end. If the detergent concentration is high enough (that is above the cmc or critical micelle concentration) the fat friendly ends self-assemble into micelles with the water-friendly ends sticking out into the surrounding water.
When the micelles comes in contact with a …

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Dynamic Light Scattering, Nanoparticle Tracking Analysis, Nanosight, Particle concentration, Particle size, Protein Aggregation, Tech Talk, Zetasizer »

[15 Sep 2016 | ]

Nanoparticle Tracking Analysis or Dynamic Light Scattering ?
After a recent joint NanoSight and Zetasizer demonstration, I received this set of questions that helps illustrate the core of the issue of these two techniques:

Since the Nanosight gives me particle concentration, it’s somewhat straightforward to calculate what % of my Nanoparticles are aggregated. Can I calculate % aggregated particles in the DLS as well?  Or does the varying amount of intensity, and the protein+nanoparticle mixture in the sample confound that calculation?

If I wanted to measure non-spherical particles (for example nanorods), which system …

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Dynamic Light Scattering, Laser Diffraction, Mastersizer, Particle size, Tech Talk, Zetasizer »

[25 Aug 2016 | ]

Size distributions are a description of the fact that not every component in the sample has the same size.  There is a range of sizes present, as mathematically described by a distribution.
There are different ways to represent this distribution in terms of:

Intensity – How much light comes from the different components?
Volume or mass – How much volume is present in the different components?
Number – How many particles are present in the different components?

This often causes confusion, and the intensity volume number issue is one of the most popular blogs.
Intuitively most …

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