Why 260/280

The ratio limits presented in this note are generally accepted ideal values. It is important to empirically determine the ratio limits that predict sample functionality in your downstream applications.

The DS Series EasyApps software provides automatic alerts for samples outside these standard values, or custom thresholds can be entered. William W. Check our help guide for more info. Introduction It is common practice for molecular biologists to use the ratio of the measured spectrophotometric absorbance of a sample at nm compared to the value measured at nm as an assessment of purity for nucleic acid and, to a lesser extent, protein samples.

Figure 1: Typical dsDNA spectrum. Figure 2: Typical BSA spectrum. Common Nucleic Acid Contaminants Despite the best efforts of the researcher, residual contaminants often remain in solution with nucleic acids following chemical isolation.

Microvolume vs. Variance From Other Instrument Brands It is not unusual to observe slight differences in purity ratios when measuring the same sample on different spectrophotometers.

Library Items. This webinar provides useful background information and many t Request More Information. Discover effective ways to enhance your UV5Nano micro-volume measurements with pipetting and sample handling best practices — perfect for busy life sc Nucleic Acid Analysis. The new poster 'Nucleic Acid Analysis with Absorbance Spectroscopy' shows in a nutshell all key information to fast and easily determinate the concent Download Poster.

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Initial crude lysate may give a high number like 1. The flowthrough may have an even higher ratio because it contains the nucleic acids that have been isolated out of the sample. The eluate should have the lowest ratio because contaminants in the flowthrough have now been removed, leaving behind pure protein.

Nucleic acid contamination does not show up on a protein gel, which is why measuring the ratio is essential for an accurate picture of purity. Great for new users!