Catalogue number: FE-100T (for 100 tests) IntroductionFeulgen reaction, first described by Robert Feulgen, is one of the most commonly used cytochemical methods for semiquantitative DNA determination in histologicaland cytological samples. It is very important to determine the exact amount and status of the DNA of the nucleus in order to make a diagnosis and treat malignanttumors. The key parameter in precise measuring of DNA is reproducibility of the Feulgen reaction. If the instructions for use are followed correctly, reproducibility iseasily and reliably achieved by using reagents found in BioGnost's Feulgen kit. BioGnost's Feulgen kit contains additional contrasting reagent for cytoplasmic stainingwhich enables easier and clearer observation of stained DNA. Using contrasting reagent is not necessary during the staining protocol, but it provides better contrast tothe stained DNA of the section.