Interlocking molecular structures known as rotaxanes have been expanded to DNA to create a new class of nanomachines for studying biological systems. Li Li and researchers at Qingdao University used DNA psuedorotaxnes as an alternative method for detecting low concentrations of mRNA in cancerous cell lines. Instead of the traditional polymerase chain reaction, a cross-rolling circular amplification synthesizes and links two DNA psuedorotaxnes into a single DNA rotaxane, which contains a biotinylated primer detected by a streptavidin coated magnetic nanoparticle. To read more about the zeptomole sensitivity and high selectivity accomplished by this assay, check out the article below.
Ultrasensitive detection of mRNA extracted from cancerous cells achieved by DNA rotaxane-based cross-rolling circle amplification
Sai Bi, Yangyang Cui and Li Li
Analyst, 2013, Advance Article