What is the purpose of feulgen staining?
Feulgen stain is a staining technique discovered by Robert Feulgen and used in histology to identify chromosomal material or DNA in cell specimens. It is darkly stained. It depends on acid hydrolysis of DNA, therefore fixating agents using strong acids should be avoided.
How do you use feulgen stain?
In a routine Feulgen staining technique, slides are immersed in 5 mol/L HCl for 15 minutes, rinsed with distilled water for 3 minutes, stained with Schiff’s reagent for 90 minutes, washed for 10 minutes and finally stained with 1% light green for 15 minutes (7-8).
What is the color reaction produced in Feulgen staining?
The Feulgen reaction is based on Schiff’s reaction for aldehydes whereby, by acid hydrolysis, the liberated aldehydes of the deoxy sugar are allowed to react with fuchsin–sulphurous acid to yield a typical magenta colour reaction.
What type of dye is Schiff’s reagent?
The Schiff reagent is the reaction product of a dye formulation such as fuchsin and sodium bisulfite; pararosaniline (which lacks an aromatic methyl group) and new fuchsin (which is uniformly mono-methylated ortho to the dye’s amine functionalities) are not dye alternatives with comparable detection chemistry.
Which chemical substances in the cells can be detected by staining the cells with methyl green and Pyronin?
The combination of methyl green with pyronin can differentiate between RNA and DNA as the DNA appears green and RNA red. It can also distinguish between single- and double-stranded DNAs, as following denaturation, single-stranded DNA is known to become pyroninophilic.
What is Schiff’s test used for?
The Schiff test is a chemical test used to check the presence of aldehydes in a solution. This is done by reacting the solution with a small quantity of Schiff’s reagent. Schiff’s reagent is the reaction product of a dye such as fuchsin and sodium bisulfite.
Do aldehydes give Schiff’s test?
Schiff’s reagent is used to distinguish between aldehydes and ketones. Ketones do not react with Schiff’s reagent; however, aldehydes react with Schiff’s reagent. Complete answer: The Schiff test is a chemical test used to check the presence of aldehydes in a solution.
Does methyl green stain tissue?
Methyl green–pyronin. Pyronin staining, on the other hand, does not show this spatial affinity and any negatively charged tissue constituent will stain red. In practice, not only RNA stains: acid mucins present in epithelium and cartilage will also stain.
How does methyl green Pyronin stain work?
Methyl green-pyronin (MGP) is a classical histological staining technique using two basic (cationic) dyes for the demonstration and differentiation of DNA and RNA. Pyronin does not possess this affinity and binds to the remaining negatively charged RNA staining it red.
How is Feulgen used to determine DNA content?
The Feulgen technique selectively stains DNA, and under controlled conditions, can be used for the photometric determination of DNA content. The reaction consits of two steps.
How is the Feulgen reaction used in biology?
It allows DNA in situ to be specifically stained based on the reaction of Schiff or Schiff-like reagents with aldehyde groups engendered in the deo … The Feulgen reaction proposed by Feulgen and Rossenbeck 75 years ago is one of the cytohistochemical reactions most widely used in biology and medicine.
How is the Feulgen staining method used in photometric testing?
FEULGEN STAINING PROTOCOL. The Feulgen technique selectively stains DNA, and under controlled conditions, can be used for the photometric determination of DNA content. The reaction consits of two steps. Fixed material is treated for 8-10 min with 1N HCl in a water bath or oven at 60°C. Afterwards, the material is immediately transferred…
Can a non hydrolyzed DNA prepare a Feulgen reaction?
Non-hydrolyzed DNA preparations will not develop a Feulgen-positive response. Fig. 3. Feulgen hydrolysis curve in which the ascending branch is due to gradual DNA depurination, the plateau represents maximal DNA depurination and the descending branch reveals the apurinic acid depolymerization.