Use of methylene blue as staining agent to reveal DNA
Methylene blue may be used as an alternative to ethidium bromide, a suspected mutagen, in staining Agarose gel to reveal DNA.
Methylene (methylthioninium chloride) blue is not classified as hazardous according to the harmonized classification nor is it notified in the C&L inventory. See also Further information.
Electrophoresis of DNA requires a staining step to make the separated DNA fragments visible. The
safest and easiest method is to use methylene blue solution. As methylene blue carries a positive
charge, it binds to the negatively charged DNA fragments and stains them blue. Two methods may be used: with diluted or with concentrated methylene blue. The method using diluted methylene blue involves submerging the gel in methylene blue solution (0.025%) and allowing it to stand for up to 16 hours so the stain diffuses into the gel and binds with the DNA fragments.
Methylene blue is a commonly used and available chemical, whose use in revealing DNA does not involve high costs or complicated laboratory procedures.It is a good substitution especially for school laboratories.
MSDS methylene blue (methylthioninium chloride) from Sigma -AldrichFurther languages available
Type of information supplier
Producer / distributor
Southern Biological, a division of Cogitamus Pty Ltd, Southern Biological
19-21 Worrell Street, Nunawading,Victoria 3131, Australia, http://www.southernbiological.com/
Southern Biological, Australia.Type of publication and availability
Document freely available on internet
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