Cary 3500 Multicell UV-Vis Spectrophotometer

The Cary 3500 Peltier UV-Vis systems offer the ability to analyze the thermal stability and profiles of biological and other molecules using temperature-controlled UV-Vis spectroscopy. In this whitepaper from Agilent Technologies, explore how to optimize experimental conditions for thermal melt measurements to achieve high-quality data with confidence.

The Cary 3500 multicell provides a new way to achieve data integrity by measuring samples, standards, and controls simultaneously. This capability eliminates environmental and operator-generated analytical variables and the resultant risk to data accuracy.

Many life science and chemical applications require a thorough understanding of the dynamics of reaction processes. Variables such as temperature, pH, pressure and the presence of additional chemical components and macromolecules can have a significant effect on reaction rates. Understanding the influence of such parameters is key for a wide variety of applications including enzyme characterization, chemical synthesis, food manufacture and industries that rely on optimized product storage and stability conditions. UV-Vis spectrophotometers are routinely used to help characterize and quantify the kinetics of reactions as they can continuously measure changes in the concentration over time as determined by the change in absorbance over time.

Measurements made by a UV-Vis spectrophotometer provide a fast and reliable quality control check of a sample. They can also be used to calculate specific activity or estimate yield after purification, and to identify fractions containing protein or amino acids.

The separation of double stranded nucleic acids into single strands can be induced by raising the temperature. At a certain temperature, the hydrogen bonding between the base pairs is broken. A thermal melt experiment exploits the difference in the number of hydrogen bonds between adenosine to thymine (A=T) and guanine to cytosine (GΞC) nucleotides for DNA, or between adenosine to uracil (A=U) and G to C for RNA. As the GΞC nucleotides contain three hydrogen bonds, the heat energy required to dissociate is greater than that of the double bonded pairs. This means that DNA and RNA containing more GΞC pairs will melt at a higher temperature. The melting temperature (Tm) gives an accurate indication of the base composition (ratio of the GΞC vs the A=T / U=T) in the sample. The Tm often used as a QC check by manufacturers and researchers.

In this podcast, Dr. Melanie Zerulla-Wernitz, Head of the Analytical Science Laboratory at Vetter Pharma, discusses the tools and techniques her team uses to optimize analytics of oligonucleotide-based pharmaceuticals. Dr. Mathieu Rault of Agilent Technologies also highlights how to execute temperature-controlled measurements of oligonucleotides and outlines the implementation of spectroscopy tools for fast, accurate ID testing.

Set temperature, equilibrate, measure, repeat? You can try it that way—or you could just do four temperatures at once. The new Agilent Cary 3500 UV-Vis lets you compress lengthy kinetics experiments into manageable time frames by measuring your samples at different temperatures simultaneously.

Measure standards first, then measure your unknowns? Sounds time-consuming. Especially when the new Agilent Cary 3500 UV-Vis lets you do both at the same time. And with the integrated multicell holder, you will never need to do an alignment again—perfect for microvolume cuvettes.

Temperature ramping at 0.1 °C/min? That might be okay, if you have time to wait. For those who want their temperature ramping results sooner, the new Agilent Cary 3500 UV-Vis allows accurate and reproducible ramping at up to 30 °C/min without the leaks, noise, and mess of a multicell holder with a water circulator.

Find all the latest developments and biggest stories in our lab essentials community and the products scientists are raving about