Methyl green-pyronin stain

Methyl Green-Pyronin Stain is a histological stain used in histopathology to differentiate between RNA and DNA in tissue samples. It is a combination of two dyes, Methyl Green and Pyronin Y, which selectively stain DNA and RNA respectively.

Composition

The Methyl Green-Pyronin Stain is composed of two main components:

• Methyl Green: This is a cationic dye that binds to the phosphate groups of DNA, staining the nuclei green.
• Pyronin Y: This is a xanthene dye that binds to RNA, staining the cytoplasm and nucleoli red.

Procedure

The staining procedure involves several steps:

1. Fixation: The tissue sample is fixed using a fixative such as formalin to preserve the tissue structure.
2. Sectioning: The fixed tissue is cut into thin sections using a microtome.
3. Staining: The tissue sections are stained with the Methyl Green-Pyronin solution.
4. Dehydration: The stained sections are dehydrated using increasing concentrations of alcohol.
5. Clearing: The sections are cleared in xylene to make them transparent.
6. Mounting: The sections are mounted on slides using a mounting medium.

Interpretation

In the stained sections, DNA appears green due to the Methyl Green, while RNA appears red due to the Pyronin Y. This allows for the differentiation between DNA and RNA in the tissue sample.

Applications

Methyl Green-Pyronin Stain is used in histopathology for the identification and differentiation of DNA and RNA in tissue samples. It is particularly useful in the study of cell cycle and cell differentiation, as well as in the diagnosis of certain diseases.

See Also

• Histology
• Histopathology
• Staining (biology)
• Methyl Green
• Pyronin Y