Rapid and sensitive homogenous detection of Ibaraki virus non-structural protein using magnetic modulation biosensing system

摘要

Magnetic modulation biosensing (MMB) system rapidly and homogeneously detected coding sequences of the non-structural Ibaraki virus protein 3 (NS3) complementary DNA (cDNA). A novel fluorescent resonance energy transfer(FRET)-based probe discriminated the target DNA from the control. When the target sequence is detected, the FRET-based probe is cleaved using Taq-polymerase activity and upon excitation with a laser beam fluorescent light isproduced. The biotinylated probes are attached to streptavidin-coupled superparamagnetic beads and are maneuveredinto oscillatory motion by applying an alternating magnetic field gradient. The beads are condensed into the detectionarea and their movement in and out of an orthogonal laser beam produces a periodic fluorescent signal that isdemodulated using synchronous detection. Condensation of the beads from the entire volume increases the signal whilemodulation separates the signal from the background noise of the non-magnetized solution. 1.9 picomolar of the Ibarakivirus NS3 cDNA was detected in homogeneous solution within 18 minutes without separation or washing steps. In thispaper we will review the magnetic modulation system and present its capability in specific DNA sequences detection.