Effect of aRNA purity and labelled-aRNA purification. (A) Graph showing coupling efficiency (C) and 320/650 (B) values for six MCF-7 aRNA samples with different 260/280 ratios. (B) Agilent Bioanalyzer pattern of MCF-7 Cy5-labelled target using an aRNA with 260/280 ratio of 1.6. Sharp spikes represent uncoupled Cy5 dye. (C) Same as B for aRNA with 260/280 ratio of 2 and coupling efficiency near 1. (D) NanoDrop® ND-1000 Spectrophotometer absorptions at 320 and 650 nm wavelengths of a MCF-7 Cy5-labelled target. 320/650 ratio-0.6. (E) Same as in d (different sample). 320/650 ratio-0.09. (F) Recovery rates (R) and coupling efficiencies (C) for different labelled-aRNA purification methods. Data is presented for MCF-7 cell line and measurements represent an average of three separate reactions. Li-ETOH – LiCl-ethanol; PCI – phenol/chloroform/isoamyl alcohol.