Fluorometric Detection of Oncogenic EML4-ALK Fusion Gene based on a Graphene Oxide System

Detection of the fusion gene composed of echinoderm microtubule-associated protein-like 4 ( EML4 ) and anaplastic lymphoma kinase ( ALK ) is important for diagnosis of lung adenocarcinoma. We developed a simple PCR-based fluorometric method for detecting the EML4-ALK fusion using a fluorescent probe DNA and graphene oxide (GO). The fluorophore-labeled probe DNA complementary to the EML4-ALK fusion junction was hydrolyzed during PCR by the 5′ to 3′ exonuclease activity of the Taq DNA polymerase. The fluorophore released from the probe DNA retained fluorescence without adsorption onto GO. Our GO-based fluorometric system was able to detect a single cancer cell harboring the EML4-ALK fusion in 10 6 wild-type cells.