Best Practice for Nucleic Acid Thermal Stability Measurements Using the Cary 3500 UV-Vis Spectrophotometer - Thermal melt (Tm) analysis using rapid, precise temperature-dependent UV-Vis absorbance measurements
UV-Vis spectrophotometers have been used widely for nucleic acid quantification and quality control (QC) utilizing the fact that nucleic acids have a maximum absorbance at 260 nm (1). The concentration of nucleic acids can be easily estimated using the absorbance at 260 nm and the established absorption coefficient. Often a background correction is also performed, for example collecting a baseline using a solution containing everything but the nucleic acid or by measuring the absorbance at a wavelength that nucleic acids do not absorb. Double stranded nucleic acids are bound by hydrogen bonds between the base pairs. The temperature at which double stranded nucleic acids denature to become single stranded depends on the: – sequence and length of the nucleic acid – the pH and buffer conditions – and any mismatches in base pairs between the two strands As such, the melting temperature is very useful analytical tool and can be studied by monitoring the absorbance at 260 nm as temperature is increased or decreased. As the temperature is increased, the hydrogen bonds between the strands are broken and the double stranded nucleic acid separates into two separate strands. When the strands separate, the absorbance at 260 nm increases. The transition temperature is called “melting temperature” (Tm) (1).
The Benefits of Custom Bonded Silica
April 1st 2025Not all chromatography resins are created equal. Off-the-shelf chromatography resins might not always meet the rigorous purification requirements of biopharmaceutical manufacturing. Custom bonded silica from Grace can address a wide range of separation challenges, leading to real performance improvements. Discover more about the latest innovations in chromatography silica from Grace, including VYDAC® and DAVISIL®.
5 Things to Consider When Selecting a Chromatography Silica
April 1st 2025Particularly in the pharmaceutical industry, drug purity isn’t just a goal – it’s essential for achieving safety, stability and efficacy. However, purification is easier said than done, especially with challenging molecules like DNA and RNA “oligonucleotides,” due in large part to their diversity and the range of impurities that can be generated during production. Enter DAVISIL® chromatographic silica, with a wide range of pore diameters and particle sizes to meet your specific application, performance and sustainability requirements. Before you choose the chromatography resin for your next purification application, take a look at these 5 considerations.
Automating Protein Purification: Efficiency, Yield, and Reproducibility
March 27th 2025Recent advancements in automated protein purification stress the importance of efficiency, scalability, and yield consistency. This eBook compares different purification platforms, highlighting their impact on downstream applications and demonstrating how automation enhances throughput and process control.
MilliporeSigma: Ultrapure Water for Sensitive LC-MS Analysis of Pesticides
March 25th 2025The aim of the study was to illustrate the efficiency of Milli-Q® water purification systems in eliminating pesticides from tap water, thereby producing and delivering reliable and consistent-quality ultrapure water suitable for pesticides analysis
