Figure 3. Quantification of P2Y₂-R mRNA levels by qRT–PCR analysis. Corneal impression cytology samples were collected at 48, 72, and 96 h after the first siRNA instillation and then submitted to total RNA isolation. After retrotranscription, we measured P2Y₂-R mRNA knockdown in corneas treated with siRNA #2. Values derived from qRT–PCR results from untreated corneas are set as 100%, and the relative expressions of corneas treated with siRNA are indicated. Three asterisks indicate p<0.001 when compared to the control.