The Starna DNACON Reference can be used for quality control and assurance of nucleic acid purity measurements using the 260/280 nm ratio method.

The ratio of the UV absorbance values at 260 nm and 280 nm is an important method for determining the purity of nucleic acid preparations, but validation actual DNA solutions is unreliable as such solutions are difficult to produce and inherently unstable. The DNACON reference from Starna was developed as a reliable, stable and NIST traceable reference material for the validation of this method. The reference consists of a solution of a synthetic material whose spectral characteristics closely mimic those of DNA, permanently heat-sealed in a far-UV quartz cell. By replicating an actual DNA sample, DNACON gives a reliable direct indication of the quality of the overall measurement process.




Absorbance values are certified at 260 nm, 280 nm and 330 nm for spectral bandwidths of 1.0, 2.0, 3.0, 4.0 and 5.0 nm . The value at 330 nm is used as a “background” correction, as in the normal methodology. From these values a corrected 260/280 ratio is calculated and reported for each bandwidth using the formula:

Ratio =      (A260 – A330)


(A280 – A330)

The typical calculated ratio is 1.9


A Certificate of Calibration and Traceability and full instructions for use are provided with each Reference Material. Starna Scientific is accredited to both ISO 17034 (4001) as a Reference Material producer, and ISO/IEC 17025 (0659) as a Calibration Laboratory for optical reference measurements. Starna offers a Lifetime Guarantee on all its Reference Materials.