A fast, low cost, and highly efficient fluorescent DNA labeling method using methyl green

Daniel Prieto, Gonzalo Aparicio, Pablo E. Morande, Flavio R. Zolessi*

*Corresponding author for this work

Research output: Contribution to journalArticleResearchpeer-review

55 Citations (Scopus)


The increasing need for multiple-labeling of cells and whole organisms for fluorescence microscopy has led to the development of hundreds of fluorophores that either directly recognize target molecules or organelles, or are attached to antibodies or other molecular probes. DNA labeling is essential to study nuclear-chromosomal structure, as well as for gel staining, but also as a usual counterstain in immunofluorescence, FISH or cytometry. However, there are currently few reliable red to far-red-emitting DNA stains that can be used. We describe herein an extremely simple, inexpensive and robust method for DNA labeling of cells and electrophoretic gels using the very well-known histological stain methyl green (MG). MG used in very low concentrations at physiological pH proved to have relatively narrow excitation and emission spectra, with peaks at 633 and 677 nm, respectively, and a very high resistance to photobleaching. It can be used in combination with other common DNA stains or antibodies without any visible interference or bleed-through. In electrophoretic gels, MG also labeled DNA in a similar way to ethidium bromide, but, as expected, it did not label RNA. Moreover, we show here that MG fluorescence can be used as a stain for direct measuring of viability by both microscopy and flow cytometry, with full correlation to ethidium bromide staining. MG is thus a very convenient alternative to currently used red-emitting DNA stains.

Original languageEnglish
Pages (from-to)335-345
Number of pages11
JournalHistochemistry and Cell Biology
Issue number3
Publication statusPublished - Sept 2014
Externally publishedYes


  • Confocal microscopy
  • DNA
  • Electrophoresis
  • Flow cytometry
  • Fluorescence
  • Methyl green


Dive into the research topics of 'A fast, low cost, and highly efficient fluorescent DNA labeling method using methyl green'. Together they form a unique fingerprint.

Cite this