Official websites use .gov A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
In this letter, the prominent biophysicist Max Delbruck asked Heidelberger for reprints of his work on the theory of the precipitin reaction, and himself proposed a mathematical theory for calculating the rate, or velocity, of antigen-antibody reactions.