Use of Zeta Potential Measurements to Characterize Good and Bad Inks

Zeta Potential of Printing Inks Offers Insights into Performance Inks for high-quality applications are frequently applied using a process by which a series of rollers acquire ink selectively according to a pattern formed on their surfaces and then transfer this ink to the printable substrate. This process is controlled by a combination of mechanically and […]

Applications: ColloidsFormulationsZeta
Instruments: NanoBrook Series

Colloidal Stability in Aqueous Suspensions

Why too much dispersant causes problems. Abstract Zeta potential in aqueous suspensions is a function of two variables: charge at the shear plane and free salt ion concentration. [Free here means not attached to the particle surface.] If a dispersant is added to increase the surface charge density (increase stability) and it’s too concentrated, the […]

Applications: ColloidsFormulations
Instruments: NanoBrook Series

BASF chooses Brookhaven again for chemicals research

BASF Agro Research, which develops chemicals for use in agriculture, has purchased a NanoBrook ZetaPALS from Brookhaven Instruments, based on Phase Analysis Light Scattering (PALS), for the determination of zeta potential of colloidal suspensions. Zeta potential is a useful indicator of a formulation’s stability. The new instrument has a particle sizing option based on DLS […]

Applications: Zeta
Instruments: NanoBrook Series

New Analysis of Red Blood Cells (RBC) using the ZetaPALS

By Bruce B. Weiner Ph.D. Introduction: 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. The zeta potential is not equal to the surface potential but rather it is the electrostatic potential difference between a rotationally averaged point at the […]

Applications: BiopharmaDiagnosticZeta
Instruments: NanoBrook Series

Molecular Weight Determination of Carbonic Anhydrase with the BI-MwA

by: John McConville, Ph.D. Size-exclusion chromatography (SEC/GPC) has been a useful technique for the determination of molecular weights of proteins. However, its usefulness is limited by the requirement for calibration of the SEC/GPC columns with standards comprising proteins of known molecular weight but which may not be of the same chemistry as the unknown protein. […]

Applications: BiopharmaEnzymesMolecular Weight
Instruments: BI-MwA

How Many Au Nanoparticles Does It Take to Circle the Earth?

Abstract Gold nanoparticles are used in a variety of applications, many pharmaceutical. The average size and the distribution play a crucial role in determining how well they work in a particular application. While TEM can show the shape of nanoparticles, it is not ideal for the statistical task of averaging the size and producing a […]

Applications: SizingTheory
Instruments: NanoBrook Series

BSA Monomer-Dimer Elucidation with the BI-MwA

Aggregation kills. Aggregated therapeutic proteins can provoke immune response and have reduced therapeutic effect. This has led to regulatory and industrial interest in identifying aggregates for elimination. Size-exclusion chromatography (SEC/GPC) has been a useful technique for the determination of molecular weights of proteins. However, its usefulness is limited by the requirement for calibration of the […]

Applications: BiopharmaChromatographyMolecular Weight
Instruments: BI-MwA

Analysis of Virus Particles in Media by Dynamic Light Scattering

Introduction 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. Virus particles incubated in the laboratory present a challenge, as they must be grown within cells […]

Applications: BiopharmaColloids
Instruments: NanoBrook Series

Absolute Size Exclusion Chromatography of BSA

Abstract We present results from Bovine Serum Albumin (BSA) measured in an analytical size exclusion chromatography (SEC) system including the Brookhaven BI-MwA static light scattering system. BSA is used ubiquitously as a test protein for concentration and for system calibration and testing. Typical results are presented. Introduction The extraction of insulin from blood plasma was […]

Applications: BiopharmaChromatographyMolecular Weight
Instruments: BI-MwA

The Measurement of Very Small Particles by Cross Correlation or Avalanche Photodiode Detectors

Walther W. Tcharnuter and Bruce. B. Weiner, Brookhaven Instruments Corporation, New York, USA (Note: this article by the founders of Brookhaven Instruments was originally published in the 1990s) The measurement of particle size using dynamic light scattering, also known as photon correlation spectroscopy, is well known. Scattered laser light is autocorrelated, fit either with cumulants […]

Applications: CrossCorrDLSSizingTheory
Instruments: BI-200SMBI-APDx