Hans Christian Joachim Gram (13 September 1853 – 14 November 1938) was a Danishbacteriologist noted for his development of the Gram stain, still a standard technique to classify bacteria and make them more visible under a microscope.
Early life and education
Gram was the son of Frederik Terkel Julius Gram, a professor of jurisprudence, and Louise Christiane Roulund.
In Berlin, in 1884, Gram developed a method for distinguishing between two major classes of bacteria.[1] This technique, known as Gram staining, continues to be a standard procedure of medical microbiology. This work gained Gram an international reputation. The staining method later played a major role in classifying bacteria. Gram was a modest man, and in his initial publication he remarked, "I have therefore published the method, although I am aware that as yet it is very defective and imperfect; but it is hoped that also in the hands of other investigators it will turn out to be useful."
A Gram stain is made using a primary stain of crystal violet and a counterstain of safranin. Bacteria that turn purple when stained are termed 'Gram-positive', while those that turn red when counterstained are termed 'Gram-negative'.
During 1891, Gram taught pharmacology, and later that year was appointed professor at the University of Copenhagen. In 1900, he resigned his professorship of pharmacology to become professor of medicine.[2] As a professor, he published four volumes of clinical lectures which became used widely in Denmark. He retired from the University of Copenhagen in 1923, and died in 1938.[2]
Popular recognition
On 13 September 2019, Google commemorated the anniversary of his birth with a Doodle for Canada, Peru, Argentina, Australia, New Zealand, Israel, India and some European countries.[3][4]
Personal life
Gram's great-granddaughter Lone Gram is a microbiologist who works at the Technical University of Denmark.[5]
