Editing Hans Christian Gram (section)

==Career==

===Gram stain===
{{Main|Gram staining}}
In [[Berlin]], in 1884, Gram developed a method for distinguishing between two major classes of [[bacteria]].<ref name=Gram_1884>{{Cite journal |author-link=Hans Christian Gram|last=Gram|first=H.C.|title=Über die isolierte Färbung der Schizomyceten in Schnitt- und Trockenpräparaten |journal=Fortschritte der Medizin |language=de|year=1884|volume=2|pages=185–189}}<br>An English translation is in {{Cite book|last=Brock|first=T.D.|year=1999|title=Milestones in Microbiology 1546–1940|edition=2|publisher=ASM Press|pages=215–218|isbn=1-55581-142-6|url=https://books.google.com/books?id=q5JHcs8w21gC&q=Milestones%20in%20Microbiology&pg=PA215}}<br />A translation is also at {{Cite web|url=http://www.hoslink.com/pathology/lab_general/history2.htm#gram|last=Brock|first=T.D.|title=Pioneers in Medical Laboratory Science: Christian Gram 1884|publisher=Hoslink|access-date=27 July 2010}}</ref> 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'.

===Other work===
Gram's initial work concerned the study of human [[red blood cell]]s. He was among the first to recognise that [[macrocyte]]s were characteristic of [[pernicious anaemia]].

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.<ref name=HardyDiag>{{cite web |title=Gram's Serendipitous Stain |author=Jay Hardy |url=http://hardydiagnostics.com/articles/Hans-Christian-Gram.pdf |access-date=13 March 2016 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304142720/http://www.hardydiagnostics.com/articles/Hans-Christian-Gram.pdf |url-status=dead }}</ref> 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.<ref name=HardyDiag/>