Figure 1

Simplified schematic overview of the gold nanoparticle (NP)-based microarray assay. The target is whole viral genome RNA (blue line), end modified capture oligos are 40 bp in length (black line) printed on the amino-modified glass slide and intermediate oligos are 65 bp in length (purple line) including 25-mer poly (A) tail (red line). The probe is 15 nm gold nanoparticles (NP) functionalized with poly dT tail (green line). The specific hybridizations between the capture oligo, RNA (or DNA) and intermediate oligo take place to form sandwich complexes in Step 1, then the gold NP probes bind to the complexes in Step 2, and silver staining is in Step 3.