Testing Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards. Inspection Validating the specifications, value and safety of your raw materials, products and assets. Certification Formally confirming that your products and services meet all trusted external and internal standards.
Assurance Testing Inspection Certification. Our network of more than 1, laboratories and offices in more than countries, delivers innovative and bespoke Assurance, Testing, Inspection and Certification solutions for our customers' operations and supply chains. Find out more. Some manufacturers may consider testing and certification an obstacle to overcome to get to market.
Others might see it as an important way to reduce risk or liability. Ensuring the Safety and Performance of Electrical Products. Global Reach Intertek is the industry leader with employees in 1, locations in over countries. Whether your business is local or global, we can help to ensure that your products meet quality, health, environmental, safety, and social accountability standards for virtually any market around the world.
Differential Scanning Calorimetry DSC Analysis Allentown Lab Powerful thermal analysis technique to determine thermal transitions of materials Differential Scanning Calorimetry DSC is a powerful thermal analysis technique in which the heat flow into or out of a sample is measured as a function of temperature or time, while the sample is exposed to a controlled temperature program.
This information can be used to determine best processing temperatures, obtaining thermal fingerprints of the materials; and comparing thermal properties of the materials with different performance ASTM E ; ASTM E Send us a request Need help or have a question? Need help or have a question? X Title. It is a very powerful technique to evaluate material properties such as glass transition temperature, melting, crystallization, specific heat capacity, cure process, purity, oxidation behavior, and thermal stability.
DSC analysis provides test data for a wide range of materials, including polymers, plastics, composites, laminates, adhesives, food, coatings, pharmaceuticals, organic materials, rubber, petroleum, chemicals, explosives, biological samples and more. DSC also measures the rate of heat flow and compares differences between the heat flow rate of the test sample and known reference materials.
The difference determines variations in material composition, crystallinity and oxidation. An example of DSC analysis: A small amount of sample mg was contained within a closed crucible and placed into a temperature-controlled DSC cell. A second crucible without sample was used as a reference. Modulated DSC which utilizes a temperature modulation technique can be used to determine weak transitions and separate overlapping thermal events. Intertek laboratory scientists offer substantial expertise in the field of thermal analysis.
Determination of endotherms, exotherms and weight loss on heating or cooling are performed. Intertek Global Website. Toggle navigation Intertek. Industries Services. Assurance Enabling you to identify and mitigate the intrinsic risk in your operations, supply chains and business processes.
Testing Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards. Inspection Validating the specifications, value and safety of your raw materials, products and assets. Certification Formally confirming that your products and services meet all trusted external and internal standards. Assurance Testing Inspection Certification.
Our network of more than 1, laboratories and offices in more than countries, delivers innovative and bespoke Assurance, Testing, Inspection and Certification solutions for our customers' operations and supply chains.
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|Differential scanning calorimetry basics of investing||Also, the rising demand for advanced differential scanning calorimetry among end user industries is expected to drive the growth of the differential scanning calorimetry market across the globe. Authors : G. The calorimetry is particularly applied to monitor the changes of phase transitions. Incorporating liquid lipids into a solid matrix will create some imperfections in the crystal lattice of nanoparticles. Langmuir ; 18 — [ Google Scholar ]. From the DSC graph, Yuan and co-workers concluded that the lower peak area ratio is a result of the reduction of nimodipine content on the surface of NLC. Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards.|
First, every protein sample must be in an even-numbered column, with the corresponding no-protein reference buffer in the odd-numbered column to its left. The machine is hard-coded to compare adjacent cells in this way; no other arrangement is allowed. Thus, comparing two conditions requires four cells — remember that each and every protein sample must have an identical-except-for-protein reference cell next to it. First, you get a distribution of T m measurements for your protein.
So if you need time to pass between one reading and another reading — for instance to check the stability of your protein over time — then your only option is to add in a bunch of blank buffer vs. This can be useful: for instance, sometimes one compound will look like it has a potential covalent liability. If it gave a particularly large thermal shift in DSC, then afterwards, you might want to throw the sample on the mass spec to see whether the compound had indeed covalently attached itself to your protein.
The protein sample should be at 0. The machine will heat the samples from some starting temperature to some finishing temperature. We would like to use DSC to study PrP, so as a first step, we ran a pilot experiment just to check the baseline melting temperature and stability in DMSO and over time. We concentrated it to 0. The blank samples at the end of row B and all of rows C and D are just to stall for time.
After loading these samples into the deepwell plate, we pressed one of the reusable plastic mats onto the top of the plate. Agreeably, the software writes out the raw data in plain-text. The key result one is interested in is the marginal amount of heat that must be added in order to achieve each additional fraction of a degree of temperature increase, in protein compared to buffer, as a function of temperature.
To wit:. You can also export a summary table as a CSV, which will just have the melting point called for each sample. As you can see from the curves above, there is actually some melting going on over a range of tens of degrees. There are also metrics for quantifying the width of the curve, for instance, the width at the half-maximal height. The conditions tested had the expected direction of effect: DMSO dose-dependently and time-dependently destabilizes PrP.
Eric Vallabh Minikel is on a lifelong quest to prevent prion disease. Follow cureffi. What and why DSC is a highly precise way of determining the melting temperature T m of a purified protein. What makes DSC unique is its specificity for the subset of small molecule ligands that do thermally stabilize a protein, whereas the other techniques will only tell you whether a small molecule binds, not whether it stabilizes.
While good practice can be achieved via a combination of rigorous training, effective method development and skilled operation, features of the latest automated DSC systems can substantially ease the analytical burden, at the same time boosting productivity, as highlighted below. An alternative approach is to use elution buffer collected during the final step of the protein purification procedure as a reference. Both techniques enhance the ability of the instrument to precisely detect changes in the specific heat capacity associated with the protein, which are small relative to the heat capacity of the solvent, thereby maximizing sensitivity.
An additional, essential element of sample preparation is sample degassing to make sure that unfolding occurs under constant volume conditions, an underlying assumption of subsequent data analysis. It is important to determine protein concentration using a suitable method, such as UV-visible spectroscopy. The molar concentration of the protein solution is required for full data analysis of the DSC thermogram, and concentration is also needed to determine the enthalpy and heat capacity changes associated with thermal denaturation.
DSC-measured parameters such as TM can be concentration-dependent, so analysis should be performed using a range of protein concentrations. Finally, when DSC is used for stability screening, the same protein concentration should be used for each sample. A buffer-buffer scan is a simple but highly effective way of confirming no measurable difference in the heat input to each cell, indicating a clean system with no contaminating sample carryover, operating correctly.
Performance checking against a known standard at regular intervals is also good practice when it comes to maintaining highly reproducible measurements. In the latest DSC systems, these repetitive but critical aspects of measurement are streamlined and automated, which is especially helpful when applying DSC in regulated environments. By providing consistent, reliable cleaning, newer DSC systems reduce the need for buffer-buffer scans and performance checking, thereby maximizing sample throughput, while at the same time enhancing data quality see Figure 3.
Figure 3: Enhanced cleaning protocols reduce the need for baseline scans, boosting sample throughput. The sixteen thermograms of ribonuclease A shown here were produced in 20 hours using an automated system, with excellent reproducibility. When it comes to running the DSC experiment, scan rate and temperature range are the primary parameters requiring careful consideration.
Scan rate is the rate at which the temperature of the cells is increased, with higher rates equating to faster analysis. However, the scan rate applied can influence the results obtained. For example, higher scan rates have been linked with broadening of the thermal transition peak in certain proteins 3.
Measuring at different scan rates during method development to determine any effect in a newly-tested sample is prudent. Again, modern systems with advanced software offer supportive features in this area, such as sample templates for the easy design, storage and duplication of identified methods.
Such features ease the programming of DSC experiments, help to eliminate user-to-user variability and, as with automated performance checking, are especially helpful for ensuring the rigor required for operation within a regulated environment. The raw output data from a DSC experiment is a plot of heat input rate as a function of temperature.
Processing this data to generate a thermogram and extract the metrics of interest involves:. This data processing can be arduous, typically involving multiple data files and an element of human decision-making, in which case consistency can also be an issue. Advances in DSC software directly address this challenge, accelerating data analysis by enabling the simultaneous processing of multiple datasets and making it easier to fully exploit the informational value of high sensitivity DSC measurements.
For example, with the latest smart software, users can simultaneously apply the same fitting method and integration baseline to multiple thermograms, to minimize subjectivity and remove inconsistency in the data analysis process. Furthermore, an established fitting method can be saved for application to other thermograms in the study, to guarantee consistent fitting methods for all samples, by all users.
This paper reviews the best-known differential scanning calorimetries (DSCs), such as conventional DSC, microelectromechanical systems-DSC, infrared-heated. It is a very powerful technique to evaluate material properties such as glass transition temperature, melting, crystallization, specific heat capacity, cure. Differential Scanning Calorimetry (DSC) is a powerful thermal analysis technique in which the heat flow into or out of a sample is measured as a function of.