Au-nanoprobe UV/Vis spectra obtained after inducing aggregation. (A) UV/Vis spectra in absence (Blank) and in presence of target (BCR-ABL target). (B) UV/Vis spectra for the detection of the BCR-ABL b3a2 fusion mRNA in total RNA from K562 cells (BCR-ABL positive cell line), HL-60 cells (BCR-ABL negative cell line), human PBMC and S. cerevisiae cells; Au-nanoprobe alone before (Au-nanoprobe + buffer) and after (Blank) salt addition. All samples in 10 mM phosphate buffer (pH 8.0). Also, spectral data from untreated Au-nanoparticles in sodium citrate.