Circularized single molecule amplification and resequencing technology (referred to as cSMART) is a gene mutation test technology with completely independent intellectual property rights, global innovation and patent protection. It is featured with 0.03% of sensitivity, precise counting and absolute
Advantages in principle
For the random fragmentation of ctDNA, cSMART first circularizes all free DNAs in the blood to form a closed cyclic structure. Then, it designs a pair of back-to-back primers near the mutation site, which are different from traditional face-to-face PCR primers. They face in opposite directions. But this pair of back-to-back primers can also perform PCR amplification because the DNA fragments have been connected into a closed loop.
Since this pair of back-to-back primers actually bind to only one region on the DNA fragment, it can be detected as long as the ctDNA contains this region, thereby solving the problem of random fragmentation of ctDNA.