Methyl green-pyronin (MGP) is a classical
histological staining
Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology (microscopic study of biological tissues), in cytology (microscopic study of cells), and in the m ...
technique using two
basic
BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College ...
(cationic) dyes for the demonstration and differentiation of
DNA and
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
.
Methyl green
Methyl green (CI 42585) is a cationic or positive charged stain, related to Ethyl Green, that has been used for staining DNA since the 19th century. It has been used for staining cell nuclei either as a part of the classical Unna-Pappenheim sta ...
is specific for
phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid .
The phosphate or orthophosphate ion is derived from phospho ...
radicals in the
DNA double helix staining it green-blue.
Pyronin does not possess this affinity and binds to the remaining negatively charged RNA staining it red. The method is useful in identifying the distribution of
Nissl substance in
neuron
A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. N ...
al cell bodies.
[Suvarna, S.K., Layton, C. and Bancroft, J.D. 2013, ''Bancroft's Theory and Practice of Histological Techniques'', 7th edn, Churchill Livingstone Elsevier]
References
Pathology
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