Fig 4. Evaluation of “standard” and commercially available decontamination procedures on human vCJD prions.

Steel wires contaminated with 10% human vCJD brain homogenate were treated with “standard” (A) and commercially available (B) prion decontamination procedures and subjected to 4 serial PMCA rounds. Two independent series of PMCA were performed on 4 wires per treatment (Black cross (Χ) Series 1 and Red square (■) Series 2). PAA: Per acetic acid 1.2%—60 min; NaOH: sodium hydroxide 0.1N—15 min or 1N—60 min; Auto: steam sterilization 121°C -20 min or 134°C -20 min; NaOCl: Sodium hypochlorite 0.2% (2000ppm)– 15 min or 2% (20000ppm)– 60 min; H₂O: untreated positive control; NEG: negative control (wire mock-contaminated with normal brain homogenate). (C) Representative Surf-PMCA results from two individual wires after both reference and marketed decontamination procedures (3F4 monoclonal antibody). Bars to the left of Western blot panels indicate the 30 and 20 kilo Dalton marker positions.