Question
Which is not a part of pap smear?
| A. | Orange G |
| B. | Eosin |
| C. |
Methylene blue |
| D. |
hematoxylin |
Show Answer
|
Correct Answer � C Explanation |
 |
Ans.C. Methylene Blue
Papanicolaou stain (also Papanicolaou’s stain and Pap stain) is a multichromatic (multicolored) cytological staining technique developed by George Papanicolaou in 1942.
- The classic form of the Papanicolaou stain involves five stains in three solutions.
- The first staining solution contains hematoxylin which stains cell nuclei.
- Papanicolaou used Harris’s hematoxylin in all three formulations of the stain he published.
- The second staining solution (designated OG-6), contains Orange G in 95% ethyl alcohol with a small amount of phosphotungstic acid. In the OG-6, the OG signifies Orange G and the ‘6’ denotes the concentration of phosphotungstic acid added; other variants are OG-5 and OG-8).
- The third staining solution is composed of three dyes, Eosin Y, Light Green SF yellowish, and Bismarck brown Y in 95% ethyl alcohol with a small amount of phosphotungstic acid and lithium carbonate.
- This solution, designated EA, followed by a number which denotes the proportion of the dyes, other formulations include EA-36, EA-50, and EA-65.
- 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. Phosphotungstic acid is added to adjust the PH of counterstains and helps to optimize the color intensity. 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.
