Papanicolaou stain

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Papanicolaou stain showing a low-grade squamous intraepithelial lesion (LSIL) from a Pap test. Cell nuclei stained blue. Low-grade squamous intraepithelial lesion.jpg
Papanicolaou stain showing a low-grade squamous intraepithelial lesion (LSIL) from a Pap test. Cell nuclei stained blue.

Papanicolaou stain (also Papanicolaou's stain and Pap stain) is a multichromatic (multicolored) cytological staining technique developed by George Papanicolaou in 1942. [1] [2] [3] The Papanicolaou stain is one of the most widely used stains in cytology, [1] where it is used to aid pathologists in making a diagnosis. Although most notable for its use in the detection of cervical cancer in the Pap test or Pap smear, it is also used to stain non-gynecological specimen preparations from a variety of bodily secretions and from small needle biopsies of organs and tissues. [4] [5] Papanicolaou published three formulations of this stain in 1942, 1954, and 1960. [2]

Contents

Usage

Pap staining is used to differentiate cells in smear preparations (in which samples are spread or smeared onto a glass microscope slide) [6] from various bodily secretions and needle biopsies; the specimens may include gynecological smears (Pap smears), sputum, brushings, washings, urine, cerebrospinal fluid, [4] abdominal fluid, pleural fluid, synovial fluid, seminal fluid, [7] fine needle aspirations, tumor touch samples, or other materials containing loose cells. [8] [4] [9]

The pap stain is not fully standardized and comes in several formulations, differing in the exact dyes used, their ratios, and the timing of the process. [2] [1] Pap staining is usually associated with cytopathology in which loose cells are examined, but the stain has also been modified and used on tissue slices. [9]

Pap test

Pap staining is used in the Pap smear (or Pap test) and is a reliable technique in cervical cancer screening in gynecology. [10]

Generalized staining method

The classic form of the Papanicolaou stain involves five stains in three solutions. [2] [11] [12]

The counterstains are dissolved in 95% ethyl alcohol which prevents cells from over staining which would obscure nuclear detail and cell outlines especially in the case when cells are overlapping on the slide. [3] [2] Phosphotungstic acid is added to adjust the pH of counterstains and helps to optimize the color intensity. [2] The EA counterstain contains Bismarck brown and phosphotungstic acid, which when in combination, cause both to precipitate out of solution, reducing the useful life of the mixture. [2]

Results

The stain should result in cells that are fairly transparent so even thicker specimens with overlapping cells can be interpreted. [2] Cell nuclei should be crisp, blue to black in color [12] [13] and the chromatin patterns of the nucleus should be well defined. Cell cytoplasm stains blue-green and keratin stains orange in color. [13] [5]

Eosin Y stains the superficial epithelial squamous cells, nucleoli, cilia, and red blood cells. [2] Light Green SF yellowish confers a blue staining for the cytoplasm of active cells such as columnar cells, parabasal squamous cells, and intermediate squamous cells. [14] Superficial cells are orange to pink, and intermediate and parabasal cells are turquoise green to blue. [12]

Ultrafast Papanicolaou stain

Ultrafast Papanicolaou stain is an alternative for the fine needle aspiration samples, developed to achieve comparable visual clarity in a significantly shorter time. The process differs in rehydration of the air-dried smear with saline, use 4% formaldehyde in 65% ethanol fixative, and use of Richard-Allan Hematoxylin-2 and Cyto-Stain, resulting in a 90-second process yielding transparent polychromatic stains. [15]

Examples of Papanicolaou stain


Papers by George N. Papanicolaou describing his stain

See also

References

  1. 1 2 3 Schulte EK (1991). "Standardization of biological dyes and stains: pitfalls and possibilities". Histochemistry. 95 (4): 319–328. doi:10.1007/BF00266958. PMID   1708749. S2CID   29628388.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Gill, Gary W. (2013). "Papanicolaou Stain". Cytopreparation. Essentials in Cytopathology. Vol. 12. pp. 143–189. doi:10.1007/978-1-4614-4933-1_10. ISBN   978-1-4614-4932-4. ISSN   1574-9053.
  3. 1 2 Chantziantoniou N, Donnelly AD, Mukherjee M, Boon ME, Austin RM (2017). "Inception and Development of the Papanicolaou Stain Method". Acta Cytol. 61 (4–5): 266–280. doi: 10.1159/000457827 . PMID   28384641.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  4. 1 2 3 Kumar, Vinay; Abbas, Abul K.; Aster, Jon C. (2013). Robbins basic pathology (9th ed.). Elsevier/Saunders. p. 910. ISBN   978-1-4377-1781-5.
  5. 1 2 Drury, R. A. B.; Wallington, E. A. (1980). Carleton's Histological Technique (5th ed.). Oxford University Press. pp. 520p. ISBN   0-19-261310-3.
  6. Stedman's medical dictionary (27th ed.). Lippincott Williams & Wilkins. 2006. ISBN   978-0683400076.
  7. Lars Björndahl; David Mortimer; Christopher L. R. Barratt (1 April 2010). A Practical Guide to Basic Laboratory Andrology. Cambridge University Press. ISBN   978-1-139-48249-3.
  8. Hoda RS (2007). "Non-gynecologic cytology on liquid-based preparations: A morphologic review of facts and artifacts". Diagnostic Cytopathology. 35 (10): 621–34. doi:10.1002/dc.20698. PMID   17854077. S2CID   38797168.
  9. 1 2 Preethi, S.; Sivapathasundharam, B. (2014). "Will modified Papanicolaou stain be the new stain for keratin?". Journal of Histotechnology. 38 (1): 9–13. doi:10.1179/2046023614Y.0000000053. ISSN   0147-8885. S2CID   84486076.
  10. 1 2 Ross, Michael H.; Pawlina, Wojciech (2016). Histology : a text and atlas : with correlated cell and molecular biology (7th ed.). Wolters Kluwer. pp. 984p. ISBN   978-1451187427.
  11. Carson, Freida L; Hladik, Christa (2009). Histotechnology: A Self-Instructional Text (3 ed.). Hong Kong: American Society for Clinical Pathology Press. pp. 361–3363. ISBN   978-0-89189-581-7.
  12. 1 2 3 4 5 6 Bancroft, John; Stevens, Alan, eds. (1982). The Theory and Practice of Histological Techniques (2nd ed.). Longman Group Limited.
  13. 1 2 Dey, Pranab (2018). "Routine Staining in Cytology Laboratory". Basic and Advanced Laboratory Techniques in Histopathology and Cytology. pp. 133–138. doi:10.1007/978-981-10-8252-8_14. ISBN   978-981-10-8251-1.
  14. Faith Mokobi (2020-09-09). "Papanicolaou Staining (Pap Stain) For Pap Smear / Pap Test".
  15. Yang GC, Alvarez II (1995). "Ultrafast Papanicolaou stain. An alternative preparation for fine needle aspiration cytology". Acta Cytol. 39 (1): 55–60. PMID   7531380.
  16. Demay, Richard (2012). "Chapter 26: Stains". The art and science of cytopathology. Chicago, IL: Am Soc Clinical Pathology. p. 1505. ISBN   978-0-89189-644-9. OCLC   761848930.