Home » Archive

Molecular structure

Multi-detector SEC for characterizing the structure of polymers and bio-molecules.

Differential Scanning Calorimetry, Dynamic Light Scattering, MicroCal, Molecular size, Molecular structure, Particle size, Protein Aggregation, Tech Talk, Zetasizer »

[16 Nov 2017 | ]

Measuring aggregation temperature using the Zetasizer

In dynamic light scattering (DLS), the hydrodynamic size and size distribution of particles in solution can be obtained.  It may be of interest to examine this measurement as a function of time and temperature, or as a ‘trend’, as it is called in the Malvern Zetasizer software.  For biological protein samples, this temperature trend is particularly interesting: although at low temperatures a protein may be stable and show repeatable size (and scattering intensity) measurements, typically at some elevated temperature (Tagg), protein molecules will show a tendency …

Read the full story »

Archimedes, Chemical identification, Label-free analysis, Malvern Panalytical Events, MicroCal, Microcalorimetry, Molecular size, Molecular structure, Molecular weight, Morphologi G3-ID, Nanosight, Particle concentration, Particle shape, Particle size, Protein Aggregation, Protein Mobility, Viscosizer TD, Zeta potential, Zetasizer »

[16 May 2017 | ]

With Pre-Conference Workshop on Biophysical Characterization and Particle Analysis
 

Date: July 17th – 20th.
We at Malvern know that protein stability is important in numerous disciplines, ranging from basic and medical biochemistry to pharmaceutical sciences. However, it is rare that researchers from all the relevant areas can join to discuss the critical issues in the field. The 2017 Colorado Protein Stability Conference provides a unique forum for this exchange of information. The topics to be covered include protein folding, dynamics and thermodynamic stability; amyloidosis and protein aggregation; and stability, formulation, analysis and processing …

Read the full story »

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 …

Read the full story »

Differential Scanning Calorimetry, Electrophoretic light scattering, Isothermal Titration Calorimetry, Label-free analysis, Malvern Panalytical Events, MicroCal, Microcalorimetry, Molecular structure, Protein Aggregation, Raman spectroscopy, Zetasizer »

[12 May 2016 | ]

I had the pleasure of participating in the 5th International Symposium on Higher Order Structure of Protein Therapeutics, also known as HOS2016, sponsored by CASSS. The meeting was at the Renaissance Hotel in Long Beach, California April 11-13, 2016. I was joined by my Malvern colleagues Rajib Ahmed and David Sanborn.
The HOS Symposium is a platform for open discussion of development and optimization of analytical techniques to study HOS of proteins and biopharmaceutical products (including monoclonal antibodies and antibody-drug conjugates), biocomparability, and biosimilars.
Protein higher order structure (HOS) includes the secondary, …

Read the full story »

Archimedes, Insitec, Kinexus, Meet the Experts, Molecular structure, Molecular weight, Particle size, Rheometry »

[12 Oct 2015 | ]

Last week my kids got very frustrated with warm French toast and a new brand of chocolate spread. The French toast, was …of course…warm, and the chocolate was misbehaving: melting and dripping on their fingers …
Now, French toast (and chocolate spread) is a staple at our house but somehow this never happened before. Mom learned the lesson fast: for this new chocolate spread let the French toast cool first! But the little neurons started firing (wonder… I know, but it happens sometimes)…
Little questions and answers in my head: why now? – …

Read the full story »

Gel permeation chromatography, Molecular size, Molecular structure, Molecular weight, OMNISEC, Size Exclusion Chromatography, Tech Talk »

[14 Jul 2015 | ]

Multi-detector SEC – 10 reasons why protein scientists need one
In a previous post I listed the top ten reasons why a polymer characterization scientist might want to upgrade to multi-detector Gel Permeation Chromatography/Size Exclusion Chromatography, but there are similar points to be made as to why a protein characterization scientist might do the same.  We often focus on the benefits of our own systems but sometimes we may miss the benefits of the basic technique.
If you are a protein characterization scientist and you find yourself thinking, “My UV detector works …

Read the full story »

Molecular size, Molecular structure, Molecular weight, Particle shape, Protein Mobility, Zetasizer »

[30 Jun 2015 | ]

The Zetasizer has some optional advanced protein features that you may not be aware of:
DLS Debye Plot: a dynamic Debye plot of the measured hydrodynamic size as a function of sample concentration to obtain the dynamic Virial coefficient (also known as kd, or interparticle interaction parameter)
Mixture Viscosity: estimates the viscosity of a mixture of dispersants of known viscosity, using the assumption that the total viscosity is a volume fraction weighted sum of the component viscosities. The mean viscosity is based on the volume fraction and the individual viscosities of the component …

Read the full story »

Molecular structure, Molecular weight, OMNISEC, Viscotek »

[23 Jun 2015 | ]

Gel Permeation Chromatography (GPC) is a very popular analytical tool for characterizing natural and synthetic polymers.  This Wednesday Dr. Wei Sen Wong will show results from Triple Detection GPC systems for various polyacrylonitrile (PAN) samples in a webinar presentation.  Molecular weight (MW) distribution and structural information (Mark-Houwink plots) are of special interest to PAN research as well as for product and process specifications (QC).  His presentation shows GPC data that differentiated PAN samples with copolymer and/or branching features.  In addition, flow injection polymer analysis (FIPA) can be a fast and reliable tool for …

Read the full story »

Gel permeation chromatography, Molecular size, Molecular structure, Molecular weight, OMNISEC, Tech Talk »

[19 Jun 2015 | ]

When we are talking to customers about advanced Gel Permeation Chromatography (GPC) systems, we can explain why ours are the best on the market or how their excellent sensitivities means you can measure polymers with lower molecular weight than ever before.  We could tell you how the latest system, OMNISEC, reduces servicing time and costs with its new design of viscometer. Sometimes though we come across the question of why someone would want to invest in a multi-detector advanced GPC system.
Maybe you are thinking, “I’ve got a conventional system with …

Read the full story »

Molecular structure, Molecular weight, Protein Aggregation »

[21 May 2015 | ]

We recently published a new application note on protein characterization using our latest SEC system, OMNISEC, and I wanted to bring your attention to this elegant piece of work that beautifully shows the kind of information you can get from a multi-detector system and, perhaps more importantly, the kind of information you might be missing from a single-detector, UV-based system.The chromatogram below shows a typical chromatogram of a standard protein,    β-amylase:

It looks pretty typical with a monomer and a small amount of aggregates, right? Wrong!
Let’s looks again with a multi-detector …

Read the full story »

Gel permeation chromatography, Malvern Panalytical Events, Molecular structure, Molecular weight, OMNISEC, Size Exclusion Chromatography, Tech Talk »

[10 Mar 2015 | ]

I’m currently at Pittcon, the annual laboratory science conference and expo.  This year it’s in New Orleans, not too far from our factory in Houston.  Since New Orleans is known for its Cajun food and the Food Labs conference is going on at the same time, it made me think of the ways OMNISEC, our latest Gel Permeation Chromatography/Size Exclusion Chromatography (GPC/SEC) system can be used to support work in the food industry.
I’m sure you know that there are plenty of polysaccharides in processed foods but did you know how …

Read the full story »

Gel permeation chromatography, Malvern Panalytical Events, Molecular structure, Molecular weight, OMNISEC, Size Exclusion Chromatography, Tech Talk »

[19 Feb 2015 | ]

Hello everyone! This is my first blog so I think I should start by introducing myself.  My name is Amy Durrell and I am the Applications Scientist for the separation products here at Malvern Instruments.  My role is very varied as I am responsible for pre-sales sample analysis and I see all sorts of samples coming to the labs.
Recently I had the chance to be involved with the launch of our new complete multi-detection SEC system, OMNISEC.  This was my first product launch, so it is something I was very excited …

Read the full story »

Gel permeation chromatography, Molecular structure, Molecular weight, OMNISEC, Size Exclusion Chromatography, Tech Talk »

[5 Feb 2015 | ]

GPC detector – OMNISEC – Your Questions Answered

Thanks so much to those of you who joined us for the launch of  OMNISEC, our new GPC/SEC system.  If you missed the event you can play it back by clicking here, to see how the new instrument can really enhance the characterization of polymers and proteins.  
Amy and I really enjoyed the launch and were thrilled by the interest it generated.  Many of you sent through questions during the event, and though I answered as many as possible inevitably there were too many to cover live.  As …

Read the full story »

Gel permeation chromatography, Malvern Panalytical Events, Molecular size, Molecular structure, Molecular weight, Size Exclusion Chromatography, Viscotek »

[21 Jan 2015 | ]

When you think of Houston, your first thought might be ‘Houston, we have a problem’ – a (mis)quote from the Apollo 13 space mission.  Home to mission control for NASA space flights, Houston has been at the center of many high tech adventures over the last 50 years.
On January 27, the Texan city will play host to a very different type of launch.  At the forefront of technology once again, our Houston team will showcase a completely new and revolutionary GPC/SEC system from Malvern Instruments. For the field of Gel …

Read the full story »

Dynamic Light Scattering, Microrheology, Molecular structure, Tech Talk, Zetasizer »

[11 Nov 2014 | ]

Rheology is concerned with understanding how materials flow. A traditional mechanical rotational rheometer measures the rheological properties by applying a stress to the sample and detecting the response to that applied perturbation in various geometries (for example ‘cup and bob’, or ‘cone and plate’). More recently, microfluidics allow access to the ultra-high shear rate regime with the added benefit of low sample volume requirement to still obtain information on the bulk sample properties.
An entirely different approach is microrheology by light scattering. Here, the diffusion of tracer particles is observed to …

Read the full story »

Molecular structure, Molecular weight, Size Exclusion Chromatography, Tech Talk, Viscotek »

[10 Oct 2014 | ]

As a Product Technical Specialist at Malvern Instruments a great part of my job is talking to customers and finding out how they are utilizing our instruments to perform new and exciting research. My role focuses on the use of Size Exclusion Chromatography (SEC) to analyze biopolymers and proteins. Following on from my recent blog post about Hyaluronic Acid I want to highlight protein research and more specifically membrane proteins.
Part of my role is to keep up to date with the latest information being published which involves me reading a …

Read the full story »

Insitec, Molecular structure, Rosand, Zetasizer »

[11 Feb 2014 | ]

In January, we hosted a webinar, with not one, but two Malvern experts who talked about ‘Optimization and characterization of nanomaterials for drug delivery applications’ in relation to Liposomes.

The webinar focused on two complementary techniques that can help liposome characterization.  If you missed the webinar, you can view a recording on our website which includes really cool videos of nanoparticle tracking analysis in action.
Following the webinar, there were more questions than we could answer in the available time, so I asked Mike Kaszuba, our Zetasizer expert, and Pauline Carnell, our …

Read the full story »

Malvern Panalytical Events, Molecular size, Molecular structure, Molecular weight, Size Exclusion Chromatography, Static Light Scattering, Tech Talk, Viscotek, Zetasizer »

[28 May 2013 | ]

Earlier this month Mark Pothecary and Paul Clarke (Product Manager and Product Group Manager respectively for Nanoparticle and Molecular Characterization) presented a webinar on a variety of analytical technologies suitable and of interest to biopharmaceutical industry. The recorded event touched on well-established characterization techniques, including light scattering (LALS/RALS/DLS) and size exclusion chromatography (GPC/SEC) and illustrated the benefits of combining complementary information for protein scientists.
This webinar was very well attended, and can still be viewed on the C&EN website here. However, due to the significant number of attendees, not all questions could be answered ‘live’ – so we thought it might be useful …

Read the full story »

Gel permeation chromatography, Molecular structure, Molecular weight, Size Exclusion Chromatography, Viscotek »

[3 May 2011 | ]
Weighing up GPC/SEC calibration strategies

As Product Group Manager here at Malvern Instruments, my portfolio of responsibilities includes products designed to characterize a wide range of materials and formulations, from complex colloids to natural and synthetic polymers including proteins. These products include Malvern’s Zetasizer family of light scattering systems and the Viscotek size exclusion chromatography (SEC) range.
Also referred to as gel permeation chromatography (GPC), SEC is a form of liquid chromatography used for the separation of macromolecules. It is a useful technique for both protein and polymer science and here at Malvern we are continuing …

Read the full story »