{{Short description|Commercial Romanowsky stain variant}} [[File:Macrophages in bronchial wash specimen -- high mag.jpg|thumb|Bronchoalveolar lavage specimen stained with Diff-Quik]] '''Diff-Quik''' is a commercial Romanowsky stain variant used to rapidly stain and differentiate a variety of pathology specimens. It is most frequently used for blood films and cytopathological smears, including fine needle aspirates.<ref name="Silverman1990">{{cite journal| author=Silverman JF, Frable WJ| title=The use of the diff-quik stain in the immediate interpretation of fine-needle aspiration biopsies. | journal=Diagnostic Cytopathology | year= 1990 | volume= 6 | issue= 5 | pages= 366–9 | pmid=1705500 | doi= 10.1002/dc.2840060516}} </ref><ref name="Lester2019">{{cite book|author=Susan C. Lester|edition=2nd|title=Diagnostic Pathology: Intraoperative Consultation|chapter-url=https://books.google.com/books?id=YjeZDwAAQBAJ&pg=PA72|date=10 May 2019|publisher=Elsevier Health Sciences|isbn=978-0-323-57020-6|page=69|chapter=Section 2: Methods - Slide preparation}}</ref><ref name="Demay2012">{{cite book | last=Demay | first=Richard | title=The art and science of cytopathology | publisher=Am Soc Clinical Pathology | location=Chicago, IL | year=2012 | isbn=978-0-89189-644-9 | oclc=761848930 | page=1505 |chapter= Chapter 26: Stains}}</ref> The Diff-Quik procedure is based on a modification of the Wright-Giemsa stain pioneered by Harleco in the 1970s,<ref name="Silverman1990"></ref> and has advantages over the routine Wright-Giemsa staining technique in that it reduces the 4-minute process into a much shorter operation and allows for selective increased eosinophilic or basophilic staining depending upon the time the smear is left in the staining solutions.<ref name="Keebler1993">{{cite book | last=Keebler | first=Catherine | title=The manual of cytotechnology | publisher=ASCP Press | location=Chicago | year=1993 | isbn=0-89189-352-0 | oclc=27435280 |edition=7th}}</ref>
There are generic brands of such stain,<ref name="Silverman1990"></ref><ref name="Dako2010"></ref> and the trade name is sometimes used loosely to refer to any such stain (much as "Coke" or "Band-Aid" are sometimes used imprecisely).
==Usage== Diff-Quik may be utilized on material which is ''air-dried'' prior to alcohol fixation rather than immersed immediately (i.e. "wet-fixed"), although immediate alcohol fixation results in improved microscopic detail.<ref name="Lester2019"></ref><ref name="Demay2012"></ref><ref name="FinnPeterson2004">{{cite book|author1=William G. Finn|author2=LoAnn C. Peterson|title=Hematopathology in Oncology|chapter-url=https://books.google.com/books?id=qi9c1xbvPyoC&pg=PA184|date=31 May 2004|publisher=Springer Science & Business Media|isbn=978-1-4020-7919-1|page=184|chapter=Role of fine needle aspiration in lymphoma}}</ref>
The primary use of Romanowsky-type stains in cytopathology is for cytoplasmic detail, while Papanicolaou stain is used for nuclear detail. Diff-Quik stain highlights cytoplasmic elements such as mucins, fat droplets and neurosecretory granules. Extracellular substances, such as free mucin, colloid, and ground substance, are also easily stained, and appear metachromatic. Major applications include blood smears, bone marrow aspirates, semen analysis and cytology of various body fluids including urine and cerebrospinal fluid.<ref>{{cite web|url=https://www.ral-diagnostics.fr/en/solutions/human-biology-haematology-cytology/ral-diff-quik/|title=RAL DIFF-QUIK|website=RAL diagnostics|accessdate=2021-06-12}}</ref><ref name="WHO2010">{{cite book | title=WHO laboratory manual for the examination and processing of human semen | url=https://archive.org/details/wholaboratoryman00orga | url-access=limited | publisher=World Health Organization | location=Geneva | year=2010 | isbn=978-92-4-154778-9 | oclc=646393549 | page=[https://archive.org/details/wholaboratoryman00orga/page/n76 62] |chapter=Part I: Semen analysis |edition= 5th}}</ref> Microbiologic agents, such as bacteria and fungi, also appear more easily in Diff-Quik.<ref name="Demay2012"/> This is useful for the detection of for example ''Helicobacter pylori'' from gastric and pyloric specimens.<ref name="Dako2010">{{cite book |last=Kumar |first1=George L. |last2=Kiernan |first2=John A. |last3=Gill |first3=Gary W. |last4=Badve |first4=Sunil |chapter-url=https://www.agilent.com/cs/library/technicaloverviews/public/08066_special_stains_eduguide.pdf |title=Education guide: Special stains and H&E |chapter=Chapter 1: Introduction to special stains |edition=2nd |publisher=Dako North America |year=2010 |page=5 |url-status=live |archive-url=https://web.archive.org/web/20190130220517/https://www.agilent.com/cs/library/technicaloverviews/public/08066_special_stains_eduguide.pdf |archive-date=2019-01-30 |access-date=2019-06-29 }}</ref>
Due to its short staining time, Diff-Quik stain is often used for initial screening of cytopathology specimens. This staining technique allows the cytotechnologist or pathologist to quickly assess the adequacy of the specimen, identify possible neoplastic or inflammatory changes, and decide whether or not additional staining is required.<ref name="Keebler1993"></ref><ref name="Meena2015">{{cite journal | last=Meena | first=Nikhil | last2=Jeffus | first2=Susanne | last3=Massoll | first3=Nicole | last4=Siegel | first4=Eric R. | last5=Korourian | first5=Soheila | last6=Chen | first6=Chien | last7=Bartter | first7=Thaddeus |display-authors=3| title=Rapid onsite evaluation: A comparison of cytopathologist and pulmonologist performance | journal=Cancer Cytopathology | publisher=Wiley | volume=124 | issue=4 | date=2015 | issn=1934-662X | doi=10.1002/cncy.21637 | pmid=26492064 | pages=279–284| doi-access=free }}</ref><ref name="Roh2015">{{cite journal | last=Roh | first=Michael H. | title=The Utilization of Cytologic Fine-Needle Aspirates of Lung Cancer for Molecular Diagnostic Testing | journal=Journal of Pathology and Translational Medicine | publisher=The Korean Society of Pathologists and The Korean Society for Cytopathology | volume=49 | issue=4 | date=2015 | issn=2383-7837 | doi=10.4132/jptm.2015.06.16 | pmid=26076721 | pages=300–309| pmc=4508567 }}</ref>
== Components == The Diff-Quik stain consists of 3 solutions:<ref name=Keebler1993></ref> *Diff-Quik fixative reagent **Triarylmethane dye **Methanol *Diff-Quik solution I (eosinophilic) **Xanthene dye (Eosin Y) **pH buffer *Diff-Quik solution II (basophilic thiazine dyes) **Methylene blue **Azure A **pH buffer
== Results == {| class="wikitable" ! Structure || Colour |- | Erythrocytes || Pink/yellowish red |- | Platelets || Violet/purple granules |- | Neutrophils || Blue nucleus, pink cytoplasm, violet granules |- | Eosinophils || Blue nucleus, blue cytoplasm, red granules |- | Basophils || Purple/dark blue nucleus, violet granules |- | Monocyte || Violet nucleus, light blue cytoplasm |- | Bacteria and fungi|| Dark blue |- |Cytoplasm, collagen and muscle|| Various shades of pink, orange, yellow and blue<ref name="Polysci">{{cite web |url=https://www.clinisciences.com/coloration-giemsa-3967/differential-quik-stain-kit-modified-351001918.html |format=PDF |title=Differential Quik Stain (Modified Giemsa) |author=Polysciences Inc. |work=Technical Data Sheet #715 |url-status=live |archive-url=https://web.archive.org/web/20190630170431/http://www.polysciences.com/skin/frontend/default/polysciences/pdf/TDS%20715.pdf |access-date=2019-06-30 |archive-date = 2019-06-30}}</ref> |- | Spermatozoa || Light blue acrosomal region, dark blue post-acrosomal region<ref name=WHO2010></ref>
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== Alternatives == *Wright Giemsa stain *Papanicolaou stain
== References == {{Reflist|30em}}
{{Romanowsky stains}}
Category:Histopathology Category:Hematopathology Category:Cytopathology Category:Romanowsky stains