Quality Control

The purpose of the Quality Control function is to verify that the products comply with the specifications, primarily with respect to purity according to HPLC or UPLC.

What is a true value of purity?

In the business, there are no standard methods or guidelines how to analyze and evaluate the purity of oligonucleotides. Therefore, it may be difficult for customers to compare results from different oligonucleotide suppliers. The measured purity of one product will differ depending on the type and brand of the analytical column but also the analytical method used.

At SGS DNA, we have a conservative and critical approach to our products and strive to present as true as possible. We use HPLC or UPLC to determine the purity,and mass spectrometry for  mass- and sequence determination. We have validated methods and in case we have several options we always choose the method or technology with the highest sensitivity, selectivity and resolution. For example, on long and complex molecules we perform the analyses on UPLC, as this technology gives more accurate information compared to HPLC technology. Comparison between the two technologies is available here.

Our analytical service is often used for trouble-shooting by diagnostic companies who not yet are our customers, and therefore we regularly analyze oligonucleotides manufactured by other manufacturers. In all cases, our analytical methods have presented a lower value than the manufacturer. This shows that our methods are conservative and have not been developed just to impress customers with high optimistic purity values. We are glad to be of assistance in trouble shooting, by combining our long experience and our state-of-the-art equipment. However, it is our aim to consistently provide our customers with products of such high quality, that our products never has to be suspected as the source of error.   

There is no universal method that will present an absolute purity value. However, the combination of different analytical methods will give you the most accurate estimate of the purity of your oligonucleotide. In our QC laboratory we use a variety of analytical methods, shown here to the right.

Available analyses:
Anion Exchange-HPLC
Reversed Phase-HPLC
Ultra Performance-LC
Mass determination (ESI-TOF)
Determination of amino reactivity