Instrument for Label-Free Detection of Noncoding RNAs

Figure 2

Overlay of two consecutive experiments to prove the detection of a 100 pM antisense strand. The graph shows the significant difference between an injection of 100 pM antisense match strand (black curve) and an injection of 100 pM antisense mismatch strand (red curve, the mismatch has two nonmatching base pairs in the centre of the target). Injecting the match sample induces approximately −200 nm differential deflection, where else the injection of the mismatch configuration leads to almost no differential signal. Phase (I) shows the recorded baseline at 10 μL/min buffer flow. (II) 1’000 μL sample injection at 100 μL/min. (III) incubation phase at 10 μL/min. (IV) flushing with buffer 100 μL/min. (V) resulting differential deflection after injection cycle is completed (10 μL/min buffer flow). Curves correspond to the differential deflection signal of positive minus reference cantilever (CL). Therefore the bending of the cantilevers is not absolute but differential deflections. The two injections were performed in series on the same cantilever array chip. A baseline correction, normalization, averaging, and differential signal calculation (probe minus reference) were done according to the literature [15]. Hatched area highlights the increased flow speed during injection and wash phase. Colored area indicates the presence of probe molecules in the flow chamber.