An allosteric DNA switch–mediated catalytic DNA circuit for ratiometric and sensitive nucleic acid detection

Abstract

Herein, a new allosteric DNA switch-mediated catalytic DNA circuit reaction strategy was proposed for ratiometric and sensitive nucleic acid detection. The sensing system was based on two DNA hybrid probes...

A two-layer circuit cascade-based DNA machine for highly sensitive miRNA imaging in living cells

“…Five thousand cells (MCF-7 cells or normal human liver cells L02 from the Cell Bank of Type Culture Collection of the Chinese Academy of Sciences) were seeded in a 4-well glass bottom confocal dish and incubated at 37 °C for 12 h. The cell transfection was performed according to a standard protocol using a commercial transfection reagent (Lipofectamine 2000, Invitrogen USA). 34 The mixture of A/B duplex (1 μL, 10 μM) and fuel strands (1 μL, 10 μM) diluted in 50 μL of Opti-MEM medium (reduced-serum medium) was incubated with 1 μL of Lipofectamine 2000 diluted in 50 μL of Opti-MEM for 20 min, followed by incubating the cells for 3 h at 37 °C. After washing with PBS twice, H1 (1 μL, 10 μM) and H2 (1 μL, 10 μM) in 50 μL of Opti-MEM medium were pre-mixed with 1 μL of Lipofectamine 2000 in 50 μL of Opti-MEM medium for 20 min and the mixture was incubated with the cells for another 3 h. The transfection mixture was removed from the confocal dishes and the cells were washed with PBS two times.…”