NanoBrook Omni Dynamic Light Scattering (DLS) Particle Sizer and zeta petential Analyzer (Brookhaven

The NanoBrook Omni particle sizer and zeta potential analyzer offers users with fast, routine, sub-micron measurements of size and zeta potential for proteins, polymers and colloidal dispersions.

Introduction

Based on the principles of Dynamic Light Scattering (DLS) for particle sizing and distribution, and on Doppler velocimetry (electrophoretic light scattering, ELS) for zeta potential, most measurements only take a minute or two. The instrument also includes Phase Analysis Light Scattering (PALS) measurements for samples with low mobilities (saline, PBS). 

SIZING

• Rapid and accurate nanoparticle size distributions

• Range: > 0.3 nm to 10 μm

 • Three measurement angles: 15°, 90°, & 173°

 • High power 35 mW diode laser

• Dynamic light scattering at 173° and 90°

 • Temperature control, -5 °C to 110 °C

 • Molecular weight determination 

ZETA POTENTIAL

• For proteins, peptides, mAb, RNA, and other biological samples

• For zeta potential in organic solvents

• For oily or viscous media

• For high-salt suspensions

• For samples near the I.E.P.

• 1,000 times more sensitive than other techniques

• Disposable cuvettes, no contamniation or alignmnent

• Built in automatic procedures and parameters (SOP)

Scattering Angles

Measurements of traditional colloids are usually made at 90° scattering angle due to the unbiased results measured. For nanoparticles and proteins, IgG and peptides, these < 50 nm samples can be measured using the backscattering angle (173°) for best S/N and reproducibility of measurements. The 15° detection angle can be selected for added sensitivity with aggregation measurements. Zeta potential measurements are always performed using the 15° detection angle to minimize diffusion broadening.

Principles of Operation - Sizing

Dilute suspensions, on the order of 0.0001 to 1.0% v/v are prepared, using suitable wetting and/or dispersing agents, if required. A small ultrasonicator is sometimes useful in breaking up loosely-held agglomerates. At 173 sample volume may be reduced to 50 μL with a polystyrene, U-shaped, disposable cuvette and the sample is recoverable. At 90° square polystyrene or glass cells (two or three mL) are used, one as small as 10 μL (non-disposable). In addition, disposable, glass round cells with reusable Teflon stoppers are used for aggressive solvent suspensions. In all case, just a few minutes are required for the sample and cell to equilibrate with the actively controlled temperature environment inside the NanoBrook Omni.

Principles of Operation - Zeta Potential

The NanoBrook Omni utilizes phase analysis light scattering to determine the electrophoretic mobility of charged, colloidal suspensions. Unlike its cousin, Laser Doppler Velocimetry (LDV, [sometimes called Laser Doppler Electrophoresis, LDE]), the PALS technique does not require the application of large fields which may result in thermal problems or denaturation, because in the measurement of phase shift, the particles need only to move a fraction of their own diameter to yield good results. In salt concentrations up to 2 molar and with electric fields as small as 1 or 2 V/cm enough movement is induced to get excellent results. In addition, the Autotracking feature compensates for thermal drift.

Specifications