(A) Quantification of RCA–RCA amplification-fold in cDNA. QRT-PCR was performed either directly from unamplified BT474 cDNA or from the RCA–RCA-amplified product for three single copy genes. Curves 1–3 CYC, GAPDH, HER2 respectively, using RCA–RCA-amplified DNA as starting material. Curves 4–6 CYC, GAPDH, and HER2 respectively, using unamplified DNA as starting material. (B) Detection of relative gene expression of BT-474 versus reference human mammary epithelial cells before and after RCA–RCA-amplification of cDNA, using Taqman realtime PCR. cDNA used for RCA–RCA amplification was obtained from the reverse transcription of ∼25 ng total RNA starting material.
