Survivin expression in primary human chondrocytes. (A) Immunoblot for survivin protein in five independent primary chondrocyte cultures (Patient No.). Protein lysates at 24 hours after transfection of a GFP siRNA and at 24 and 48 hours after transfection of a survivin-specific siRNA are shown. (B) Relative expression of survivin RNA after transfection of the specific siRNA detected by quantitative PCR. One representative chondrocyte culture is shown.