A Short Guide to Differential Scanning Calorimetry Processes and Technology
Differential Scanning Calorimetry (known as DSC) defined simply, is a way of measuring and assessing heat energy intake, commonly in studies with polymers, liquid crystals, drugs and general chemical analysis.
It’s an enormously effective and useful technique that has a wide range of applications in a large number of fields. Here, we will explain how it works, where it’s used, and what features to look out for.
How does DSC work?
DSC is a technique used to study biochemical reactions as a molecule transitions from one conformation to another (the easiest and most obvious example of which is a sample’s melting point). There are two approaches including heat-flux and power-compensated DSCs.
The heat-flux DSC operates by leveraging two separate enclosed “pans.” One pan has the sample material and is placed on a thermoelectric disc that has been surrounded by a furnace. It’s important that the furnace is brought up – in terms of heat – at a consistent rate as it transfers heat through the pan to the sample.
The other pan is kept empty but is heated by the same furnace. There will be a difference in the temperatures of the two pans, as a result of the heat capacity of the sample. And from there, by leveraging the thermal equivalent of Ohm’s law (q=ΔT/R), it is possible to determine the heat flow.
This test requires the use of two separate pans as well as two separate heaters. Again, one will have the sample, and the other will not. By maintaining both pans at the same temperature, there will be a difference in the thermal power required – owing to the sample in one – and researchers can measure and plot that difference as a function of both temperature and time.
The application and value of DSC for researchers
So, what is DSC used for, and how is this technique valuable to researchers?
Using DSC technology for Biology
In biology, the formation of unique structures of macromolecules (proteins being one example) is known to be reversible, and these reactions are thermodynamically driven. DSC as a technique can be used to evaluate the factors that play a role in protein stability.
The use of heat also helps researchers observe fusion and crystallisation events, measure glass transition temperatures, and study chemical reactions such as oxidation. As temperatures rise, the molecules within the amorphous (or non-crystalline solid) will gain enough freedom to arrange themselves into a crystalline form. There’s a great deal of value to researchers in being able to measure this crystallisation temperature.
The pharmaceutical approach in using DSC
Another common and useful application of DSC is in drug analysis and discovery. Widely used in pharmaceutical industries, the DSC technique allows a researcher to study curing processes, and research the cross-linking of polymer molecules. In pharmaceuticals, it’s important that the components of a drug are precise, especially for the many drugs which require delivery in amorphous form. In order to ensure that, it’s important that the drug company is informed of the temperature in which crystallisation would occur. That way, they can keep their manufacturing and processing facilities optimised and operating below that temperature.
Other benefits of DSC to medical research is that the technology can be used to detect and eliminate component candidates that are more likely to bring stability issues to the drug.
What are the important technical features needed for DSC?
The technology required for DSC is, of course, highly specialised, and there are a number of critical features that you’ll need in order to maximise the value of the technology.
Firstly, and perhaps most obviously, DSC technology needs to be highly sensitive. The lower the active cell volume, the better for researchers, because they’re often working with a very limited number of precious samples.
Speed and automation
The speed in which you can work with the machine is also of critical importance. And, the more the process is automated, the better. A high quality machine will handle all the filling, injection, and all cleaning functions to facilitate “walk-away” operation, and a good machine should handle dozens of samples per day.
Finding a quality DSC product
The MicroCal PEAQ-DSC Automated is a good example of the kind of advanced technology that really benefits researchers. It can measure very tight binding constants, (up to 1020M-1) and
can screen up to 50 samples per day, with a sample capacity of 288 (6 × 96-well plates), and full 24 hour unattended throughput. The MicroCal PEAQ-DSC Automated is the kind of automated technology that allows researchers to focus on more advanced tasks while providing comprehensive and exacting data.
Additionally – and this is important for DSC – molecules can be studied in their native state without labelling using the MicroCal PEAQ-DSC Automated. Solutions that interfere with optical measurements, such as particulate or coloured samples, can still be measured with highest accuracy.
For more information on the MicroCal PEAQ-DSC Automated, and how this fully integrated platform can help you or your researchers in delivering high quality results from biology to nanoscience, contact us at ATA Scientific.