Applications and Articles - Testa Analytical Solutions

Why is Flow Rate Important in GPC/SEC?

To obtain reliable data from your GPC/SEC instrument - each run should be related to a calibration curve obtained by measuring appropriate chromatographic standards. Calculations from GPC/SEC experiments are based on elution volume, which is a product of time and flow rate...Read More

Particle Sizing: what is Baseline Index and why is it important?

The baseline index, abbreviated as BI, is a metric that can be used to quantify the impact of dust contamination on a given DLS measurement. Within the vernacular of light scattering, dust is often loosely defined, referring to any minor component too large to properly disperse, moving due to gravity, rather than Brownian motion...Read More

Static Light Scattering of Biomacromolecules

Static Light Scattering (SLS) is capable of measuring the average molecular weight of polydisperse materials, as well as of samples with discrete aggregation numbers, such as proteins. Synthetic polymers are intrinsically polydisperse and are well-suited to direct analysis using this technique, thus the meaning of an average molecular weight is more direct...Read More

Powerful Tools for Drug Delivery Characterization

Liposomes are commonly used in drug delivery applications to encapsulate and deliver bioactive cargo molecules such as oligonucleotides and proteins. A new application is available that discusses how Liposomes may be characterized using Dynamic Light Scattering (DLS) and Zeta Potential techniques...Read More

Real-Time Monitoring of HPLC Pump Performance

High Performance Liquid Chromatography (HPLC) is nowadays one of the most widely used techniques in analytical chemistry. The range of applications soluble using HPLC covers a vast range of sample types, concentrations, and compositions. This extreme flexibility is achieved by using specific columns carefully designed for each particular investigation...Read More

How Enhanced Detector Stability Leads to Improved GPC/SEC Results

GPC (Gel Permeation Chromatography) or SEC (Size-Exclusion-Chromatography is widely acknowledged as one of the most useful characterization methods in polymer science. The technique offers the possibility to determine molecular weight distribution and its averages, to provide a complete picture of the polymer sample under investigation...Read More

How Does Baseline Index Impact DLS?

Nanosphere Research Using Dynamic Light Scattering

Science Direct presented a study entitled, “Self-Assembly Of B-Cyclodextrin And Pluronic Into Hollow Nanospheres In Aqueous Solution” which investigated self-assembly of b-cyclodextrin (b-CD) and tri-block pluronic (PEG–PPG–PEG) in an aqueous solution...Read More

Light Scattering: a key Tool for Performance Polymer Characterisation

The majority of modern performance polymers are designed to enhance a particular material property. A number of high-profile engineering plastics, resins, and gels are made from these kinds of precursors. Light scattering can be used to solve many of the unique problems encountered when working with unusual functional plastics and associated polymeric precursors...Read More

Automation of pH-titrations using the BI-ZTU

The stability of dispersible nanomaterials often depends on having a high surface charge. These charges are often pH dependent, especially for surface chemistries with acidic or basic functionalities. A titration can be performed to rapidly profile a range of solution conditions to determine...Read More

Enclosed Light Scattering Instruments and Goniometer Based Light Scattering Instruments - A Comparison

When the acquisition of a new instrument for particle sizing is being considered, two options are presented: a goniometer based or an enclosed light scattering instrument... Read More

High Performance GPC/SEC System

Gel-permeation chromatography (GPC) coupled with Multi-Angle Static Light Scattering (SLS) is a modern and powerful technique for determining absolute molecular weight values without the need to rely on traditional column calibration... Read More

Analysis of Virus Particles in Media by Dynamic Light Scattering

Traditional visual methods of observing virus particles in solution give a snapshot of a very small sampling volume, while the technique of particle analysis using dynamic light scattering yields an ensemble average of particles present in the solutions... Read More

Light Scattering Probes the Properties of Complex Colloids

The BI-200SM dynamic and static light scattering goniometer and BI-9000AT correlator as a photon correlation spectroscopy system has helped the Bristol Colloid Centre, a commercial enterprise founded by the University of Bristol (UK), probe the properties of a variety of complex colloidal systems... Read More

Guide to Making Useful Measurements of Monoclonal Antibodies (mAbs) with Dynamic Light Scattering

DLS relies on the principle that freely diffusing material, moving randomly due to Brownian motion, will produce rapid fluctuations in scattered laser light.... Read More

Using ZetaPALS to make High Salt Zeta Potential Measurements on Red Blood Cells

Zeta potential is a useful property to know for colloids, nanoparticles, and proteins. It is a substitute for the otherwise hard to measure surface charge... Read More

Why is Ionic Strength Relevant to DLS Measurements?

The measurement of particle size by dynamic light scattering (DLS) is heavily dependent on the stability of materials being investigated... Read More

NanoBrook 90Plus Particle Size Analyzer Effective in Poorna Chandrodayan Research

Anoop Austin from Rumi Herbals’ R&D Centre, presented a study that demonstrated mercurial and gold preparation in nanoparticle form. The study was entitled... Read More

Why are DLS measurements in high concentration solutions difficult?

Dynamic Light Scattering (DLS) is an effective measurement technique used for measuring the hydrodynamic size of common nanomaterials including colloids, nanoparticles, proteins, and polymers... Read More

Strain specificity in antimicrobial activity of silver and copper nanoparticles

The antimicrobial properties of silver and copper nanoparticles were investigated using Escherichia coli (four strains), Bacillus subtilis and Staphylococcus aureus (three strains)... Read More

Micellar Water Characterization: A Laser Light Scattering Application

Micellar waters are the trendy new facial cleanser that boasts its ability to clean skin without irritation. We present results from dynamic light scattering (DLS), phase analysis light scattering (PALS)... Read More

Comparing Goniometer Based & Enclosed Light Scattering Instruments

A new technical note is available from Testa Analytical that describes the principal advantages of Goniometer based light scattering over the traditional Dynamic Light Scattering (DLS) or Static Light Scattering (SLS) techniques... Read More

Aggregation Detection by Dynamic Light Scattering

Testa Analytical Solutions e.K reports on how its NanoBrook Omni particle size analyser and BI-ZTU autotitrator can be used together to detect the onset of aggregation in nanoparticles... Read More

Characterising Liposomes & Liposome-drug Conjugates

Liposomes or Lipid-drug conjugates used as targeted drug delivery systems are hot topics in the field of pharmaceutical research... Read More

What is a particle

Elementary vs Fine Particles: The question embodied in the title might seem strange until you consider the many... Read More

What is Particle Size Distribution Weighting

Some particle size instruments determine size for individual particles. They are single particle counters. Some instruments... Read More

A guide to choosing a Particle Sizer

Introduction: The choice of a particle Size analyzer has never been more difficult. There are several techniques from which to choose and variations within... Read More

A Guide to Determination of Particle Size

When any material of one phase is dispersed into a second phase, an "interface" is created between the two phases... Read More

A Guide to Proper Sample Preparation

Introduction: Sample preparation is the most important step in obtaining the best results for both dynamic and static light scattering ... Read More

New advances in the Zeta Potential measurements of proteins

Stability of protein formulations is of critical importance for the rapidly emerging areas of protein therapeutics and vaccine... Read More

Studying Protein Aggregation Using ASEC

Exploiting the potential of protein therapeutics requires the ability to identify and quantify the protein aggregation that can yield... Read More

Particle Sizing using DCP for ASTM Carbon Black

The principles of particle sizing using a disc centrifuge photosedimentometer are reviewed. The importance of the extinction... Read More

Guide for DLS sample preparation

This document is intended to help the user determine the best way to prepare samples for dynamic light scattering (DLS) measurements... Read More

Determination of specific refractive index increment (dn/dc)

The specific refractive index increment (dn/dc) is a fundamental parameter for the determination of molecular weight with Static Light Scattering... Read More

Common detectors for GPC/SEC Chromatography

This article provides an overview about the detectors most commonly used in GPC/SEC applications, explains differencies... Read More

Interview: Insights from Industry

In the eyes of Testa Analytical polymer characterization in terms of chromatography and particle sizing using DLS are just... Read More

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