Although Avery, MacLeod, and McCarty showed in 1944 that nucleic acid was both necessary and sufficient for the transfer of bacterial genetic traits, protein was still suspected to be a critical component of viral heredity. Alfred Hershey and Martha Chase showed that this hypothesis was incorrect with a simple experiment involving the use of a food blender. The Hershey-Chase conclusion has since been upheld numerous times, the most recent by a modern-day experiment using real-time fluorescence.