Editing Gram stain (section)

== Uses ==
[[File:Candida Gram stain.jpg|thumb|right|Gram stain of ''[[Candida albicans]]'' from a vaginal swab. The small oval [[chlamydospore]]s are 2–4 [[micrometre|μm]] in diameter.]]
Gram staining is a [[bacteriology|bacteriological]] [[laboratory]] technique<ref name=Sherris2>{{cite book |editor1-last=Ryan |editor1-first=K. J. |editor2-last=Ray |editor2-first=C. G. |title=Sherris Medical Microbiology |pages=232f |edition=4th |publisher=McGraw Hill |date=2004 |isbn=978-0838585290}}</ref> used to differentiate [[Bacterium|bacterial]] species into two large groups ([[gram-positive]] and [[gram-negative]]) based on the physical properties of their [[cell wall]]s.<ref name="Madigan_2004">{{cite book |last1=Madigan |first1=M. T. |last2=Martinko |first2=J. |last3=Parker |first3=J. |title=Brock Biology of Microorganisms |edition=10th |publisher=Lippincott Williams & Wilkins |date=2004 |isbn=978-0-13-066271-2 |url-access=registration |url= https://archive.org/details/brockbiologyofmi00madi}}</ref>{{page needed|date=March 2016}}  Gram staining can also be used to diagnose a [[fungal infection]].<ref name="medline2021"/> Gram staining is not used to classify [[archaea]], since these microorganisms yield widely varying responses that do not follow their [[Phylogenetics|phylogenetic groups]].<ref>{{cite journal |last=Beveridge |first=T. J. |title=Use of the Gram stain in microbiology |journal=Biotechnic & Histochemistry |volume=76 |issue=3 |pages=111–118 |date=2001 |pmid=11475313 |doi=10.1080/714028139}}</ref>

Gram stains are performed on [[body fluid]] or [[biopsy]] when [[infection]] is suspected. Gram stains yield results much more quickly than [[microbiological culture|culturing]], and are especially important when infection would make an important difference in the patient's treatment and prognosis; examples are [[cerebrospinal fluid]] for [[meningitis]] and [[synovial fluid]] for [[septic arthritis]].<ref name="Sherris" /><ref name="Søgaard_2007">{{cite journal |last1=Søgaard |first1=M. |last2=Nørgaard |first2=M. |last3=Schønheyder |first3=H. |title=First notification of positive blood cultures: High accuracy of the Gram stain report |journal=Journal of Clinical Microbiology |volume=45 |issue=4 |pages=1113–1117 |date=2007 |pmid=17301283 |doi=10.1128/JCM.02523-06 |pmc=1865800}}</ref>