posted 01-04-2017 09:39 PM            

SubX® kit is uses a new method of circulating cell-free DNA (cfDNA) isolation from liquid biopsies (plasma or serum). Our technology is based on using the proprietary bi-functional substance (SubX®) that binds DNA under physiological conditions (e.g. directly in biological liquids), followed by adsorption of [DNA- SubX®] complex on a solid phase matrix. Since SubX® captures DNA via phosphate residues (groups) it allows for elimination of bias related to both AT/CG content and DNA fragments length, thus improving extraction efficacy and accuracy of downstream applications. All currently available commercial kits are [silica-chaotropic salt]-based and exhibit bias for either short or long DNA fragments, as well as for the GC content. In addition, such systems suffer from lot-to-lot minor surface differences of silica that results in variations of extraction efficiency of small DNA fragments. Our approach eliminates these problems.
The first step of all commercial [silica-chaotropic salt]-based kits includes at least 4- fold dilution of starting volume of bio liquid with concentrated (~5.0 M) guanidine thiocyanate (GTC) to keep resulted GTC concentration at about least 3.0 M. As a result, already low concentrations of cfDNA are further (significantly) reduced and may negatively influence extraction efficacy of low abundance DNA fragments. Since our method does not require chaotropic salt for DNA capture, no dilution of starting material (and thus cfDNA) will take place.