Feulgen staining method

Stacey also initiated a study of the widely used Dische and Feulgen staining methods. When he commenced his investigations, knowledge of the chemical basis of the tests was limited, although there was extensive literature on applications of the Feulgen reaction. 

Eleven plant species (Table 3) were preliminarly tested for their response to the Feulgen staining method (described below), which is essential for the efficient microscope observation of genetic anomalies of cells. This, in order to select plants to be successively used in the experiments with the mutagenic compounds. 

Oostveldt P van, Boeken G. Absorption cytophotometry evaluation of three methods for the determination of DNA in Feulgen stained nuclei. Histochemistry 1976 50 147-159. 

Use For staining Tubercle bacillus and in distinguishing between the coli and aerogenes types of bacteria in the Endo medium. Also used in the periodic acid-Schiff (PAS) method, in the Feulgen stain, and in the Gomoris aldehyde-function method for staining elastic tissue. 

Although they absorb ultraviolet light, the nucleic acids of the nucleoli are not stained with the Feulgen reagent and disappear after treatment with ribonuclease. Small amounts of ribonucleic acid are also associated with the chromosome and, finally, after chromosomal nucleic acid is digested, the presence of the basic proteins can be revealed by adequate staining methods. 

Recent Advances in Microbiological Methods. Chemistry of Gram Staining and of the Feulgen and Dische Reactions for Nuclear Material, M. Stacey, Nature, 171 (1953) 507. 

To give some idea of the results CHO cells pulse labelled with [3H]thymidine were stained with either ethidium bromide or using the acriflavin-Feulgen method (again staining DNA) and submitted to flow microfluorometry and cell sorting. 

Embryos operated on as just described can be smdied by a variety of methods, according to the question being addressed. Fix the embryo in methanol (for most immunological detection procedures), Zenker s fixative (for Feulgen-Rossenbeck staining), or 4% formaldehyde in PBS (for in-situ hybridization and most other procedures). Details on these procedures may be found elsewhere in this volume and in (10). 

The continuity of the DNA in the chromosome has been further demonstrated with dyes more sensitive than those classically used in the Feulgen preparation. By carefully determining the amount of DNA in the interband area by cytophotometric methods. Swift [31] ruled out the possibility that each chromosome is made up of a large number of strands, each corresponding to a DNA molecule. He claims that the existence of many strands is physically impossible many strands could not be stacked within the area occupied by interbands, and a multistranded structure would yield staining characteristics much more marked than those in the interband. 

DNA is localized in the cell nucleus, more specifically in the chromosomes. This has been demonstrated by Feulgen s reaction (Feulgen s nuclear staining) which is specific for DNA and stains only the chromosomes. Optical methods (measurements of ultraviolet absorption) have corroborated these observations. 

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