Naphthol Yellow S

for microscopy (Hist.), for the precipitation (of amino acids and peptides)

Flavianic acid sodium salt, 5,7-Dinitro-8-hydroxy-2-naphthalenesulfonic acid sodium salt, 2,4-Dinitro-1-naphthol-7-sulfonic acid sodium salt, Acid Yellow 1
Empirical Formula (Hill Notation):
CAS Number:
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PubChem Substance ID:

Quality Level


for microscopy (Hist.)
for the precipitation (of amino acids and peptides)




hematology: suitable
histology: suitable


methanol: water (1:1): 0.5 g/10 mL, clear


≥275 at 423-433 nm in water
≥≥ 250 at 387-397 nm in water

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room temp

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Naphthol yellow S has been used as a staining agent in fixed human embryonic stem cell-derived cardiomyocytes.

Biochem/physiol Actions

Naphthol yellow S (NYS) is used as a stain for protein basic groups. It is an acidic dye and forms a NYS-protein complex at acidic pH. Combination of feulgen and NYS provides DNA to protein ratio.

Analysis Note

λmax. ∼428 nm/∼392 nm; E(1%,1 cm) ∼275-425/∼250-400 (H2O)


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Hazard Statements

Precautionary Statements

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves


NONH for all modes of transport

WGK Germany


Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis
Certificate of Origin
Scholtissek C, et al.
Chemistry and Cytochemistry of Nucleic Acids and Nuclear Proteins (2012)
J Gaub
The Histochemical journal, 13(5), 717-722 (1981-09-01)
Owing to the accumulation of nuclear non-histone protein (NHP) (a) in cells entering the cell cycle from the quiescent state and (b) in continuously cycling cells during G1 phase, a simultaneous determination of DNA and nuclear NHP is of high...
S Gutschmidt et al.
Histochemistry, 72(3), 467-479 (1981-01-01)
In order to quantify the amount of protein in the small intestinal brush border region at different villus sites, cryostat sections of adult rat jejunum were stained with Naphthol Yellow S, Dinitrofluorobenzene and Coomassie Brilliant Blue and the dye deposits...
P Skehan et al.
In vitro cellular & developmental biology : journal of the Tissue Culture Association, 21(5), 288-290 (1985-05-01)
A rapid method has been developed for measuring the cellular protein content of mono- and multilayered anchorage cultures. Fixed or air dried cultures are stained for 30 min with 0.2% Naphthol Yellow S (NYS) dissolved in 1% acetic acid. Unbound...
M S Huang et al.
Chest, 88(6), 864-869 (1985-12-01)
In order to study differences in the tumor growth and frequency of metastases between younger and older patients with lung cancer, we investigated the nuclear DNA and nuclear protein according to age by means of cytophotometry after combined staining with...

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