Figure 4.

Quantum dot-based in situ hybridization is quantitative. The signal intensity as determined by quantitative spectral imaging (A: magnification, ×40) was compared with that obtained from the same cells by RT-PCR. LNCaP cells were grown in charcoal-stripped serum and subsequently stimulated with the synthetic androgen R1881 and harvested at 2, 9.5, and 24 hours. Transcript levels of the androgen-regulated gene FAS were evaluated both at the tissue level and by quantitative RT-PCR. Quantitation of FAS mRNA by spectral images of FFPE LNCaP cells (A and B) was highly correlated with FAS mRNA expression as determined by quantitation of transcript by quantitative RT-PCR (C and D).