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  • Dynamic Light Scattering Measurement in High Concentration Solutions...Read More

  • Assessing Nanoparticle Antimicrobial Properties...Read More

  • Zeta Potential Measurement on Scarce, Concentrated or Sensitive Samples...Read More

  • Quantitative, High Resolution X-Ray Particle Sizing...Read More

  • Light Scattering Goniometer Reveals Why Molybdenum Solutions Are Blue...Read More

  • Aggregation Detection by Dynamic Light Scattering...Read More

  • Characterising Liposomes & Liposome-Drug Conjugates...Read More

  • Accurate Determination of Structure & Branching in Complex Polymers...Read More

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    Dynamic Light Scattering Measurement in High Concentration Solutions

    Testa Analytical Solutions e.K announces a comprehensive new applications study that explains why making Dynamic Light Scattering (DLS) measurements in concentrated solutions is difficult.

    Dynamic Light Scattering is a widely used and effective technique for measuring the hydrodynamic size of common materials including colloids, nanoparticles, proteins, and polymers.

    Despite the versatility of this technique, the study discusses two major factors that impact the ability to measure particle size at high concentrations: multiple scattering and interparticle interactions.

    The authors of the study conclude that even in the absence of multiple scattering, measurements made in the semi-dilute region do not necessarily reveal particle size, and thus great care must be used to interpret such results. It is also demonstrated that serial dilution can be used to identify the region in which the sample is sufficiently dilute to reliably calculate particle size directly.

    The NanoBrook Omni particle sizer and zeta potential analyzer from Testa Analytical provides users with fast, routine, sub-micron measurements of size and zeta potential for proteins, polymers and colloidal dispersion applications. 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 such as saline and PBS.

    For a copy of the new application study please visit www.testa-analytical.com/index.html?dc=Knowledge&sn=18. For further information on the NanoBrook Omni please visit www.testa-analytical.com/index.html?dc=Particle&sn=1 or contact Testa Analytical Solutions on +49-30-864-24076 / info@testa-analytical.com.

     

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    Assessing Nanoparticle Antimicrobial Properties

    Testa Analytical Solutions e.K. reports on how a BI-200SM light scattering goniometer has been used to help assess the antimicrobial properties of silver and copper nanoparticles.

    In the study, various strains of Escherichia coli, Bacillus subtilis and Staphylococcus Aureus were treated with suspensions of suspended silver and copper nanoparticles. To assess the effectiveness of the nanoparticles, a BI-200SM goniometer was used to measure the size of the suspended nanoparticles by obtaining particle size distribution data via dynamic light scattering (DLS).

    Carlo Dessy, Managing Director of Testa Analytical commented "Silver and copper ions have been known to have antimicrobial properties and are used as superior disinfectants for wastewater generated from hospitals containing infectious microorganisms. Learning how to manipulate these silver and copper nanoparticles can lead to discoveries that may greatly impact applications in the fields of medical devices, food processing, and water treatment". He added " I am very pleased to see that the BI-200SM goniometer has helped the researchers that undertook this study to conclude "silver and copper nanoparticles show great promise as antimicrobial agents against Escherichia coli, Bacillus subtilis and Staphylococcus Aureus."

    The Bl-200SM goniometer system is a precision research grade instrument designed for exacting light scattering measurements. Based on a special turntable with precision ball bearings and stepping motor, the Bl-200SM's modular, automated design and quality construction guarantee precise measurements due to the wobble-free movement of the detector. As you would expect from a research grade system the BI-200SM can measure light scattering over a wide angular range (8° to 155° with 25 mm cells) and offers fine adjustment of measurement angles to 0.01° directly using a large, fine-control knob. Fine-screw vertical adjustment makes centre of rotation measurement easier when aligning cells. Precise repeatable data is ensured by automated heating and cooling of the sample cell using and standard external recirculating system. Field proven in hundreds of labs around the world the BI-200SM light scattering goniometer system is ideal for even the most demanding macromolecular studies and submicron particle sizing applications.

    For a full copy of this study please visit www.testa-analytical.com/index.html?dc=Knowledge&sn=17. For further information on the BI-200SM research goniometer system please visit www.testa-analytical.com/index.html?dc=Scattering&sn=1 or contact Testa Analytical Solutions on +49-30-864-24076 / info@testa-analytical.com.

     

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    Zeta Potential Measurement on Scarce, Concentrated or Sensitive Samples

    Testa Analytical Solutions e.K. has introduced a Small Volume Electrode (BI-SVE175) that pushes the boundaries of Zeta Potential measurement. Its novel design minimizes waste and preserves expensive or scarce samples with its ability to measure Zeta Potential from a sample volume of just 175 microliters.

    Not only does the BI-SVE175 preserve samples, it can measure sensitive samples such as proteins without denaturing them. In addition, its use of low voltage allows samples with extremely high salt concentration to be measured without difficulty. 

    The BI-SVE175 small volume  electrode has been designed to operate optimally with Testa Analytical's NanoBrook series of Zeta Potential instruments.

    Although it is used in the same way as a standard electrode cell on NanoBrook series instruments, the BI-SVE175 enables accurate and repeatable Zeta Potential measurements in highly concentrated samples. By requiring less sample dilution, using the BI-SVE175 more closely preserves the pH and chemical structure of your sample, thereby producing more directly representative measurements.

    This capability is particularly beneficial for many colloidal materials, where measuring the sample in its native state avoids the need for the often complicated centrifugation and dilution procedures needed to maintain sample integrity.

    To watch a video demonstrating how the BI-SVE175 small volume electrode can enhance your zeta potential measurements please visit https://www.testa-analytical.com/index.html?dc=Zeta&sn=5. For further information please contact Testa Analytical Solutions on +49-30-864-24076 / .

     


    Quantitative, High Resolution X-Ray Particle Sizing

    Testa Analytical Solutions e.K announce its BI-XDC X-Ray Disc Centrifuge is enabling scientists to make accurate, high resolution particle size distribution measurements, from nanometres to tens of micrometres, without time consuming calibration or absorption correction.

    Based on the principle of photosedimentation, the BI-XDC measures the size of particles according to the time the particle takes to sediment in the detector according to Stokes law. Combining centrifugal and gravitational sedimentation in a single instrument the BI-XDC sets a new standard for these well-established methods of particle sizing.

    Leveraging a highly reliable orthogonal method, the BI-XDC is proven to give error free quantitative measurements across a broad range of samples including nanoparticles, minerals, clays, ceramics and metal oxides.

    Using the Bl-XDC there are no optical corrections and no optical properties to worry about, just a simple mass sensitive response based on x-ray absorption.  The BI-XDC features a reproducible digitally controlled disk speed to ensure high performance and accuracy. The proprietary scanning x-ray head enables measurements to be made typically in just 8 minutes.

    For further information on the BI-XDC X-Ray Disc Centrifuge please visit www.testa-analytical.com/index.html?dc=Particle&sn=6 or contact Testa Analytical Solutions on +49-30-864-24076 / info@testa-analytical.com.

     

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    Light Scattering Goniometer Reveals Why Molybdenum Solutions Are Blue

    Testa Analytical Solutions e.K reports on how a BI-200SM light scattering goniometer system with autocorrelator has helped researchers at a prestigious government laboratory to solve the enigma of why aqueous molybdenum solutions are blue.

    A spokesperson from the Department of Physics at the government laboratory said "Molybdenum and oxygen can combine to form a wide variety of structures, and some polyoxomolybdate (POM) molecules are the biggest inorganic molecules known, achieving similar sizes to proteins". He added "The electronic state of the POMs is responsible for imparting a blue color to the surrounding solution, as the giant POMs cluster together rather than existing as single ions. Because of the size of the POMs, we realized we could use our BI-200SM light scattering goniometer to find out the actual structure of the complexes and we subsequently discovered a unique blackberry arrangement that we believe represents a new, stable solute state. It has changed our understanding of the solution behavior of inorganic molecules when they reach nanometer sizes."

    The Bl-200SM goniometer system is a precision research grade instrument designed for exacting light scattering measurements. Based on a special turntable with precision ball bearings and stepping motor, the Bl-200SM's modular, automated design and quality construction guarantee precise measurements due to the wobble-free movement of the detector. As you would expect from a research grade system the BI-200SM can measure light scattering over a wide angular range (8° to 155° with 25 mm cells) and offers fine adjustment of measurement angles to 0.01° directly using a large, fine-control knob. Fine-screw vertical adjustment makes centre of rotation measurement easier when aligning cells. Precise repeatable data is ensured by automated heating and cooling of the sample cell using and standard external recirculating system. Field proven in hundreds of labs around the world the BI-200SM light scattering goniometer system is ideal for even the most demanding macromolecular studies and submicron particle sizing applications.

    For further information on the BI-200SM research goniometer system please visit www.testa-analytical.com/index.html?dc=Scattering&sn=1 or contact Testa Analytical Solutions on +49-30-864-24076 / info@testa-analytical.com.

     

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    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.

    The NanoBrook Omni instrument offers a single powerful and accurate solution for particle sizing and zeta potential analysis. The instrument allows users to measure samples in nearly every possible suspension environment from high salts such as PBS and sea water to organic solvents and aqueous solutions. The instrument offers unmatched particle sizing, with the highest sensitivity, utilizing three light scattering measurement angles for truly unbiased measurement results. The BI-ZTU autotitrator option for the NanoBrook Omni provides an ideal solution for automated measurement of particle size as a function of pH.

    Applications that use iron oxide nanoparticles are vast and growing due to its stability, low toxicity, and magnetic properties. Given the great potential for applications using iron oxide, it is highly desirable to understand the effect of chemical changes to the surface of the nanoparticle.

    Aggregation of nanoparticles can occur due to changes in pH or temperature. In a new applications report* researchers show how Dynamic light Scattering (DLS) offers a quick and easy way of determining the effective diameter (or size) of iron oxide nanoparticles and an autotitrator can help automate the process of detecting changes in particle size as a function of pH. They conclude that the NanoBrook Omni particle size analyser and BI-ZTU autotitrator provide a highly effective instrumental solution for the detection on aggregation of nanoparticles due to changes in pH.

    For a copy of the application report please go to www.testa-analytical.com/index.html?dc=Knowledge&sn=14. For further information on the NanoBrook Omni instrument please visit www.testa-analytical.com/index.html?dc=Zeta&sn=1 or contact Testa Analytical Solutions on +49-30-864-24076 / info@testa-analytical.com.

     

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    Characterising Liposomes & Liposome-Drug Conjugates

    Testa Analytical Solutions e.K reports on a growing number of customers using their Nanobrook ZetaPALS instrument to accurately determine the size and surface charge of liposomes, exosomes and microvesicles.

    Liposomes or Lipid-drug conjugates used as targeted drug delivery systems are hot topics in the field of pharmaceutical research. The size and charge at the surface of the particle plays a deciding role for proper gastrointestinal uptake of the synthesized Liposome Drug Conjugates (LDC) nanoparticles and their systemic clearance by the reticuloendothelial system. It is therefore always important to determine the size of LDC nanoparticles accurately.

    A new application note is available describing how the Nanobrook ZetaPALS instrument, using a phase analysis light scattering technique, has been used to accurately determine the size and surface charge of liposomes, exosomes and microvesicles.

    The NanoBrook ZetaPALS is a highly accurate and easy-to-use Zeta Potential Analyzer using Phase Analysis Light Scattering (PALS).  This revolutionary instrument has been designed to eliminate the short comings inherent in other zeta potential instruments. Using the PALS configuration, the Nanobrook ZetaPALS can be used to measure mobilities up to 3 orders of magnitude lower than with a conventional laser Doppler electrophoresis system. The NanoBrook ZetaPALS measures complete electrophoretic mobility distributions in just seconds.

    For a copy of the application note please visit www.testa-analytical.com/index.html?dc=Knowledge&sn=13. For further information on the NanoBrook ZetaPALS instrument please visit www.testa-analytical.com/index.html?dc=Zeta&sn=4 or contact Testa Analytical Solutions on +49-30-864-24076 / info@testa-analytical.com.

     

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    Accurate Determination of Structure & Branching in Complex Polymers

    The AYE Combo Refractometer / Viscometer from Testa Analytical Solutions e.K. sets a new standard for the detection of intrinsic viscosity of highly diluted samples.

    This unique instrument is designed to have a high performance refractometer as an integral part of the viscometer, therefore both concentration and viscosity are measured at exactly the same time on the very same sample segment.

    As a consequence the AYE Combo Refractometer / Viscometer allows a much more accurate determination of molecular parameters and is particular suitable for applications focused on determining the structure and branching of complex polymers.

    Using a viscometer within a GPC/SEC System, requires a source of a concentration signal to complete the necessary calculations. The limitation of using a standard Differential Refractive Index (DRI) detector for this task, is that it must deliver a corresponding concentration signal for each point on the viscosity curve. This is possible with two separate instruments, precision of the results however, will be limited due to the volume difference of the detectors. A combination instrument, such as the AYE Combo, where both detectors are integral part of each other, overcomes these limitations and allows a much better determination of the sample under investigation.

    For further information on the AYE Combo Refractometer / Viscometer please visit www.testa-analytical.com/index.html?dc=AYE&sn=2 or contact Testa Analytical Solutions on +49-30-864-24076 / info@testa-analytical.com.

     

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