Editing Hans Christian Gram

{{Short description|Danish bacteriologist (1853–1938)}}
{{Use dmy dates|date=September 2019}}
{{Infobox scientist
| name              = Hans Christian Gram
| image             = File:Hans Christian Gram portrait by Hansen & Weller.jpg
| caption           = Hans Christian Gram by Hansen & Weller
| birth_name        = Hans Christian Joachim Gram
| birth_date        = {{Birth date|1853|09|13|df=y}}
| birth_place       = [[Copenhagen]], Denmark
| death_date        = {{Death date and age|1938|11|14|1853|09|13|df=y}}
| death_place       = Copenhagen, Denmark
| citizenship       =
| nationality       = 
| ethnicity         = 
| field             = [[Bacteriology]]
| work_institutions = 
| alma_mater        = 
| doctoral_advisor  = [[Japetus Steenstrup]]
| doctoral_students = 
| known_for         = Inventing the Gram stain
| author_abbrev_bot = 
| author_abbrev_zoo = 
| influences        = 
| influenced        = 
| prizes            = 
| footnotes         = 
| signature         =  
}}

'''Hans Christian Joachim Gram''' (13 September 1853 – 14 November 1938) was a [[Denmark|Danish]] [[bacteriologist]] 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.

He studied at the [[University of Copenhagen]], and was an assistant for [[botany]] to the zoologist [[Japetus Steenstrup]]. His study of plants introduced him to the basics of [[pharmacology]] and the use of the [[microscope]].

Gram began medical school in 1878 and graduated in 1883. He traveled throughout Europe between 1878 and 1885.

==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/>

==Popular recognition==
On 13 September 2019, [[Google]] commemorated the anniversary of his birth with a [[Google Doodle|Doodle]] for Canada, Peru, Argentina, Australia, New Zealand, Israel, India and some European countries.<ref>{{cite web |title=Hans Christian Gram's 166th Birthday| website=Google.com| date=13 September 2019 | url=https://doodles.google/doodle/hans-christian-grams-166th-birthday/| access-date=13 September 2019}}</ref><ref>{{cite news|url=https://www.independent.co.uk/news/science/hans-christian-gram-google-doodle-who-science-denmark-bacteria-death-a9103296.html |archive-url=https://ghostarchive.org/archive/20220509/https://www.independent.co.uk/news/science/hans-christian-gram-google-doodle-who-science-denmark-bacteria-death-a9103296.html |archive-date=9 May 2022 |url-access=subscription |url-status=live|title=Who was Hans Christian Gram and what did the groundbreaking scientist discover?|newspaper=Independent UK |date=13 September 2019|first=Clémence|last=Michallon|access-date=13 September 2019}}</ref>

== Personal life ==
Gram's great-granddaughter [[Lone Gram]] is a microbiologist who works at the Technical University of Denmark.<ref>{{Cite web|last=Shekhar|first=Akarsh|date=2020-10-22|title=Hans Christian Gram: 8 Facts About The Man Who Invented the Famous ‘Stain Technique’|url=https://www.dailyhawker.co.uk/hans-christian-gram/|access-date=2022-01-15|website=DailyHawker|language=en-US}}</ref>

==References==
{{Reflist}}

==External links==
{{Commons category}}
*{{cite book |author1=Whitworth, Judith A. |author-link=Judith Whitworth |author2=Firkin, Barry G. |title=Dictionary of medical eponyms |publisher=Parthenon |location=Carnforth, Lancs |year=2002 |isbn=1-85070-333-7 |url-access=registration |url=https://archive.org/details/dictionaryofmedi0000firk }} 
*{{WhoNamedIt|doctor|696|Hans Christian Joachim Gram}}

{{Authority control}}

{{DEFAULTSORT:Gram, Hans Christian}}
[[Category:1853 births]]
[[Category:1938 deaths]]
[[Category:Danish bacteriologists]]
[[Category:Danish microbiologists]]