counterstain การใช้

• A suitable basic stain is often used as a counterstain.
• This is the classic counterstain in both Gram stains, and endospore staining.
• Both Gram-positive bacteria and Gram-negative bacteria pick up the counterstain.
• In Masson's trichrome it is used as a counterstain to acid fuchsin.
• A malachite green counterstain gives a blue-green background cast to the surrounding tissue.
• PTAH is ideal for demonstrating striated muscle fibers and mitochondria, often without a counterstain.
• The aim of staining is to reveal cellular components; counterstains are used to provide contrast.
• The counterstain, however, is unseen on Gram-positive bacteria because of the darker crystal violet stain.
• This medium generally contains DAPI ( a DNA counterstain ) and an antifade solution to preserve the PNA fluorescence and reduce photobleaching.
• During the staining process, " E . coli " picks up the color of the counterstain safranin and stains pink.
• It is used as a general stain in histology, as a counterstain in combination with other dyes, and for many staining methods.
• Counterstain, which is usually positively charged safranin or basic fuchsine, is applied last to give decolorized gram-negative bacteria a pink or red color.
• Also in Gram staining, crystal violet stains only Gram-positive bacteria, and safranin counterstain is applied which stains all cells, even allowing the identification of Gram-negative bacteria as well.
• Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain ( safranin or fuchsine ) and appear red or pink.
• Gram staining uses two dyes : Crystal violet and Fuchsin or Safranin ( the counterstain ) to differentiate between Gram-positive bacteria ( large Peptidoglycan layer on outer surface of cell ) and Gram-negative bacteria.
• Gram-positive bacteria retain the crystal violet dye, and thus are stained violet, while the Gram-negative bacteria do not; after washing, a counterstain is added ( commonly safranin or fuchsine ) that will stain these Gram-negative bacteria a pink color.
• Used at a 0.001 % concentration and allowed to stain a gel after electrophoresis for 30 minutes, it can detect as little as 16ng of DNA . Through use of a methyl orange counterstain and a more complex staining method, sensitivity can be improved further to 8 ng of DNA . When crystal violet is used as an alternative to fluorescent stains, it is not necessary to use ultraviolet illumination; this has made crystal violet popular as a means of avoiding UV-induced DNA destruction when performing DNA cloning " in vitro ".