Ablation of prion protein immunoreactivity by heating in saturated calcium hydroxide.

BACKGROUND: Prions, the infectious agents that cause transmissible spongiform encephalopathies (TSEs), are relatively resistant to destruction by physical, enzymatic, and chemical treatments. Hydrolysis in boiling saturated calcium hydroxide (limewater) utilizes inexpensive chemicals to digest protein components of offal. The purpose of this work was to determine if incubating brain material from scrapie-infected sheep in near-boiling saturated calcium hydroxide solution (Ca(OH)2) would abolish immunoreactivity of the infectious prion (PrPSc) as determined by western blot.

FINDINGS: After incubating for as few as 10 minutes in saturated calcium hydroxide at 99 degrees C, immunoreactivity of protease resistant bands by western blot analysis is completely lost.

CONCLUSION: Boiling in limewater may offer an alternative for disposal of carcasses and enable alternative uses for rendered products from potentially infected carcasses.