Hans Christian Gram

Hans Christian Joachim Gram (September 13, 1853 - November 14, 1928) was a Danish bacteriologist.

He travelled throughout Europe between 1878 and 1885. In Berlin, in 1884, he developed a method for distinguishing between two major classes of bacteria. This technique, the Gram Stain, continues to be a standard procedure in medical microbiology.

In 1891, Gram taught as a professor at the University of Copenhagen.