The world’s most widely used system for nanoparticle, colloid and protein size, zeta potential and molecular weight measurements.
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 …
Dynamic Light Scattering, Electrophoretic light scattering, Meet the Experts, Static Light Scattering, Zeta potential, Zetasizer »
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) …
Français, Meet the Experts, Zeta potential, Zetasizer »
Les deuxièmes ateliers de l’IFTS (Institut de Filtration et des Techniques Séparatives) auront lieu les 15 et 16 mars à Foulayronnes (près d’Agen).
Cette année, ces ateliers seront dédiés à la caractérisation des boues et suspensions.
Le mercredi 15 mars, de 15H15 à 15H30, Michel Terray et Alain Blasco présenteront le Zetasizer WT, appareil pour la mesure en ligne du potentiel zêta lors d’une conférence intitulée “Process control of water treatment and filtration by zeta potential measurement” contenant :
Intérêt du potentiel zêta dans le suivi de floculation
Exemple d’application chez Wemlinger et Severn Trent Water
Retour d’expérience basé sur …
Dynamic Light Scattering, Molecular size, Particle concentration, Particle size, Protein Aggregation, Tech Talk, Zetasizer »
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 …
Meet the Experts, Molecular weight, OMNISEC, Particle size, Tech Talk, Zeta potential, Zetasizer »
Malvern Instruments takes part at the 8th International Symposium on the Separation and Characterization of Natural and Synthetic Macromolecules (SCM-8) at Rhone Events & Congrescenter. The main interest of the conference is the separation and characterization of large molecules. The target audience includes specialists from analytical chemistry, polymer science, and life-science communities.
Malvern is a sponsor of the conference so keep an eye out for us at our booth. In addition, I will give a talk on Thursday February, 2nd about ‘Combining Multi-Detector GPC Measurements with Ultra-High Performance GPC Separations’. The …
Electrophoretic mobility measurements from proteins: How to protect proteins in an electric field
What is the protein mobility mode?
When applying an electric field to a sample containing protein molecules, there are a few considerations to take into account to avoid “over-stressing” delicate biomolecules. The force a charged object experiences in an electric field is proportional to its charge times the electric field. Therefore the electric field strength (defined by the applied voltage divided by the distance between the electrodes, in V/cm) is more relevant than the absolute value of the applied …
Dynamic Light Scattering, Molecular size, Molecular structure, Particle size, Tech Talk, Zetasizer »
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 …Read the full story »
Inside Malvern, Zetasizer »
It’s lovely to work in the Malvern Instruments Headquarter at this time of year. Our usually functional but slightly dull open plan offices are festooned with festive decorations, as each team and department tries to out-do the rest with the flashiest and gaudiest display possible. Of all the departments at Malvern, NPI (New Product Introduction) has really gone to town this year. Maybe that’s because they have a secret weapon…. snazzy 3D printed, all singing, all dancing, exclusively designed decorations.
For the second year running, Rowena Innocent, Engineering Director, had organised a friendly competition to …
Dynamic Light Scattering, Français, Laser Diffraction, Malvern Events, Meet the Experts, Nanosight, Particle size, Static Light Scattering, Zetasizer »
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 …
Malvern Events, Zetasizer »
When it comes to maintaining a stable water treatment operation, the right coagulant dose is critical for efficient flocculation. Traditional methods for setting this parameter are imprecise and labor intensive, and as a result, over- and under-dosing is common and response to process changes is reactive at best.
At the American Water Works Association’s (AWWA) Water Quality Technical Conference (WQTC) in Indianapolis, on November 13-15, Malvern will be showcasing its Zetasizer WT which helps water treatment plants better manage coagulation control.
The Malvern Zetasizer WT provides unique benefits unavailable by other methods:
Fully automated …Read the full story »
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 …
Customer experience, Dynamic Light Scattering, Electrophoretic light scattering, Molecular size, Molecular weight, Particle size, Zeta potential, Zetasizer »
How can I save paper and print a Zetasizer report as a PDF?
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 …
The 7th International Conference and exhibition on Water Wastewater and Environmental Monitoring (WWEM) will take place at Telford, England on 2-3 November 2016.
We are giving a workshop on Thursday 3rd at 11:00 (in room 7).
This is “A brief introduction to zeta potential and sizing techniques in the water industry” and will mainly be focused on zeta potential which is gaining popularity as a monitor of particle instability to optimize the addition of expensive treatment chemicals, ultimately saving money.
Seasonal and geographical variation means the amount of chemical coagulant that needs …
Dynamic Light Scattering, Electrophoretic light scattering, Meet the Experts, Particle size, Protein Aggregation, Zeta potential, Zetasizer »
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 …
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 …
Dynamic Light Scattering, Nanoparticle Tracking Analysis, Nanosight, Particle concentration, Particle size, Protein Aggregation, Tech Talk, Zetasizer »
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 …Read the full story »
Dynamic Light Scattering, Laser Diffraction, Mastersizer, Particle size, Tech Talk, Zetasizer »
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 …
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 …
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 …
“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, …