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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.

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

[16 Aug 2016 | ]

Why are my particles measuring too small?
The technique of  Dynamic Light Scattering (DLS) has become quite standard in many biophysical characterization labs, often alongside common tools like UV-Vis, SEC, AUC, Fluorescence, NMR, AFM, SAXS, or Mass Spec.  As DLS systems (like the Malvern Zetasizer Nano) have become ever easier to use we see an increasing range of applications and research. By observing and analyzing intensity fluctuations in a sample, we can find the diffusion coefficient and, with known viscosity, the corresponding size. Inevitably, at some point the size measured will not …

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

[2 Aug 2016 | ]

Ink formulation screening: Tools for increased throughput
I thought I would take this opportunity to share some data that was collected in one of our laboratories at the Malvern Instruments headquarters in the UK. We have been working with various  batches of blue and red inks, and using the Zetasizer Nano ZSP to measure parameters related to the performance of ink formulations (such as particle size).
Utilizing the Zetasizer NanoSampler (our automated sample introduction accessory), this not only allowed the instrument to measure the samples unsupervised (even overnight!), but we were able to …

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

[21 Jul 2016 | ]

“What is dynamic light scattering?” Find out in less than 5 minutes!
Although we’ve gone into deeper detail in previous posts , every once in a while it’s nice to recap on the basics. A few years ago, our presentation “Dynamic Light Scattering Primer” was among the top three recordings in the Malvern charts for months in a row. Over the last decade, DLS has  become one of the de facto nanoparticle characterization standard methods. And it’s used not only for nanoparticles, but also for molecules, proteins, drug delivery particles, liposomes, virus like particles, …

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

[23 Jun 2016 | ]

Analysis of Mushroom Farming – Mushrooms meet Malvern
Malvern Instruments has made its name in particle sizing: the flagships Mastersizer and  Zetasizer have become the de facto global standard tools for particle sizing from nanometers to millimeters.  The breadth of applications for these technologies is simply astounding and we are constantly seeing new uses in diverse areas. As just one example, the video below shows use of a Mastersizer 2000 in a Lingzhi mushroom research facility, where state-of-the-art cultivation techniques are developed and improved.

The Lingzhi mushroom is also known as the reishi mushroom and …

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

[15 Jun 2016 | ]

Have you ever seen a peak at small size that you think just should not be there?
This can happen under certain conditions, and it is usually due to the signal from the buffer component in the sample. Ultimately, the high sensitivity of today’s dynamic light scattering (DLS) systems like the Zetasizer Nano has increased the observable range both in terms of concentration and size, thus ever smaller molecules can be detected (with the caveat that the required concentration has to be increased in order to see them, as the laws …

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

[3 Mar 2016 | ]

For fluorescent samples (like quantum dots) the Zetasizer has an option that can minimize the effect of (incoherent and thus undesirable for dynamic light scattering) fluorescent light: the narrow band filter eliminates most light that is not very close to the laser wavelength.
Narrow band filter – how it works and specifications
The narrow band filter is an optical component made out of glass with a special coating to reflect light outside the designated wavelength range. Only a select range (in the illustration, the red light) can be transmitted.
In the Zetasizer, the …

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