Surface Plasmon Resonance Imaging Sensing For Detection Of BCR/ABL Fusion Gene

Surface plasmon resonance is a physical phenomenon that occurs at the interface between the metal thin film and the dielectric.The change in the refractive index is tracked by the coupling of incident light into a propagating surface plasmon on a gold surface in real time.Accordingly,the rate of association during association phase,the rate of disassociation when target molecules is removed from the continuous flow by buffer washing,and the association rate constant and dissociation rate constant can be determined by SPR evaluation of binding kinetics.Surface plasmon resonance imaging is a new,label-free and high-throughput optical sensing technology that integrates SPR technology,CCD imaging and arrayed chips,and it is widely used in the study of biomolecule interactions.Chimeric BCR/ABL fusion gene is involved and plays a crucial role in the evolution of chronic myelogenous leukemia(CML).Determination of BCR/ABL fusion gene is important for early diagnosis,prognosis,and even better for CML patients during the treatment.In this work,an acustom-made intensity-interrogation surface plasmon resonance imaging(SPRi)system has been developed to directly detect a specific sequence of BCR/ABL fusion gene in chronic myelogenous leukemia(CML).The variation in the reflected light intensity detected from the sensor chip composed of gold islands array is proportional to the change of refractive index due to the selective hybridization of surface-bound DNA probes with target ss DNA.SPRi measurements were performed with different concentrations of synthetic target DNA sequence.The calibration curve of synthetic target sequence shows a good relationship between the concentration of synthetic target and the change of reflected light intensity.The detection limit of this SPRi measurement could approach 10.29 nM.By comparing SPRi images,the target ssDNA and non-complementary DNA sequence are able to be distinguished.This SPRi system has been applied for assay of BCR/ABL fusion gene extracted from real samples.This nucleic acid-based SPRi biosensor therefore offers an alternative high-effective,high-throughput label-free tool for DNA detection in biomedical research and molecular diagnosis.