Ueber die bakterientödtende Wirkung des zellenfreien Blutserums.

Following Nuttall’s work, Buchner discovered a substance in blood serum that was capable of destroying bacteria. He called the substance "alexin". He demonstrated that the bactericidal power of defibrinated blood was possessed by the cell-free serum, and was lost on heating the serum to 55°C for one hour.