Analysis of endogenous MMP1 gene transcription by quantitative-PCR. MeWo cells were treated with different concentration (0, 10, 30, 50, 70, 90 nM) of target designed siRNA (506 siRNA and 859 siRNA) and incubated for 24 h. After incubation, the total RNA was extracted using TRIzol Reagent. The cDNA was synthesized using 1 μg of total RNA by reverse-transcription using iScript™ cDNA synthesis kit. MMP1 and GAPDH gene expression was carried out using Quantitative-PCR/iQ™ SYBR ® Green Supermix (Bio-rad, California). (A) was the 1.5% agarose gel electrophoresis assay of the PCR products of different siRNA treatments. (B) was the quantified results of the expression quantity of relative expression of the MMP1 mRNA normalized against GAPDH mRNA and compared to blank (without treatment of siRNA).