Czapek medium

{{Short description|Medium for growing fungi in a lab}}

File:Aspergillus tubingensis FJBJ11.png growing on Czapek medium]]

Czapek medium, also called Czapek's agar (CZA){{cite web|author1=|title=Czapek Agar (CZA) Recipe|url=http://www.thelabrat.com/protocols/CzapekAgarRecipe.shtml|website=theLabRat.com|accessdate=7 November 2017|language=English|date=2005|quote=Czapek Agar (CZA) Recipe|archive-url=https://web.archive.org/web/20150316141421/http://thelabrat.com/protocols/CzapekAgarRecipe.shtml|archive-date=16 March 2015|url-status=live}}{{cite web|author1=|title=NRRL Medium No. 8 Czapek's Solution Agar ( CZA )|url=https://nrrl.ncaur.usda.gov/forms/NRRL_Medium_8.pdf|website=ARS (NRRL) Culture Collection|publisher=ARS Culture Collection National Center for Agricultural Utilization Research|accessdate=7 November 2017|location=Peoria, IL|language=English|quote=Czapek’s Solution Agar ( CZA )|archive-url=https://web.archive.org/web/20161227134000/https://nrrl.ncaur.usda.gov/forms/NRRL_Medium_8.pdf|archive-date=27 December 2016|url-status=live}} or Czapek-Dox medium, is a growth medium for propagating fungi and other organisms in a laboratory. It was named after its inventors, Czech botanist Friedrich Johann Franz Czapek (May 16, 1868 – July 31, 1921) and American chemist Arthur Wayland Dox (September 19, 1882 – 1954). It was developed to grow Aspergillus niger and Penicillium camemberti. It works well for many saprophytic fungi and soil bacteria such as species of Aspergillus, Candida, Penicillium, and Paecilomyces.{{cite web|author1=|title=CZAPEK-DOX AGAR|url=https://catalog.hardydiagnostics.com/cp_prod/Content/hugo/Czapek-DoxAgar.html|website=Hardy Diagnostics Instructions for Use|publisher=Hardy Diagnostics|accessdate=3 October 2017|location=Santa Maria, CA|language=English|archive-url=https://web.archive.org/web/20170708203455/https://catalog.hardydiagnostics.com/cp_prod/Content/hugo/Czapek-DoxAgar.html|archive-date=8 July 2017|url-status=live}}

File:Aspergillus bertholletius - Journal.pone.0042480.g004.png on Czapek agar]]

Friedrich Czapek's original recipe is as follows:{{cite journal |last= Czapek |first= F |title= Untersuchungen über die Stickstoffgewinnung und Eiweifsbildung der Pflanzen |trans-title= Studies on nitrogen production and protein formation of plants |journal= Beiträge zur chemischen Physiologie und Pathologie |date= 1901–1902 |volume= 1 |issue= 12 |pages= 538–560 |url= https://www.biodiversitylibrary.org/page/39459974 |accessdate= 2 October 2017 |language= German |format= PDF |oclc= 1519369 |archive-url= https://web.archive.org/web/20180328091820/https://www.biodiversitylibrary.org/page/39459974 |archive-date= 28 March 2018 |url-status= live }}

• 1000 g distilled water
• 30 g cane sugar – energy source and sole source of carbon{{cite web|author1=|title=CZAPEK MEDIUM|url=https://tools.thermofisher.com/content/sfs/manuals/IFU9322.pdf|website=Thermo Fisher Scientific|publisher=Remel|accessdate=3 October 2017|location=Lenexa, KS|language=English|date=September 20, 2007|archive-url=https://web.archive.org/web/20171117070331/https://tools.thermofisher.com/content/sfs/manuals/IFU9322.pdf|archive-date=17 November 2017|url-status=live}}
• 1 g dipotassium phosphate – buffering agent
• 0.5 g magnesium sulfate – source of cations
• 0.5 g potassium chloride – source of essential ions
• 0.01 g iron sulfate – source of cations

File:Aspergillus fumigatus.jpg on Czapek agar]]

Arthur Wayland Dox added 2 g of sodium nitrate in his version, to provide a sole source of nitrogen that is inorganic.{{cite journal|last1=Dox|first1=Arthur Wayland|title=The intracellular enzyms of penicillium and aspergillus: with special reference to those of Penicillium camemberti|journal=Bulletin (United States Bureau of Animal Industry)|url=https://books.google.com/books?id=iOS7chsvBwQC&q=potassium&pg=PA38|date=1910|volume=120|page=37|accessdate=3 October 2017|language=English|format=PDF|oclc=22281943|archive-date=6 October 2022|archive-url=https://web.archive.org/web/20221006014550/https://books.google.com/books?id=iOS7chsvBwQC&q=potassium&pg=PA38|url-status=live}} This makes the medium a selective growth medium as only organisms that can use inorganic nitrogen can grow. Czapek and Dox did not add agar but many recipes add 15 g to make a solid medium.