Neutral Red (or toluylene red, Basic Red 5, or C.I. 50040) is a eurhodin dye used for staining in histology. It stains lysosomes red. It is used as a general stain in histology, as a counterstain in combination with other dyes, and for many staining methods. Together with Janus Green B, it is used to stain embryonal tissues and supravital staining of blood. Can be used for staining Golgi apparatus in cells and Nissl granules in neurons.
Neutral red can be used as a vital stain, to stain living cells. It is used to stain cell cultures for plate titration of viruses.
Neutral Red is added to some growth media for bacteria and cell cultures. It usually comes as a chloride salt.
Neutral Red acts as a pH indicator, changing from red to yellow between the pH 6.8-8.0.
Famous quotes containing the words neutral and/or red:
“The lonely Earth amid the balls
That hurry through the eternal halls,
A makeweight flying to the void,
Supplemental asteroid,
Or compensatory spark,
Shoots across the neutral Dark.”
—Ralph Waldo Emerson (1803–1882)
“What journeyings on foot and on horseback through the wilderness, to preach the gospel to these minks and muskrats! who first, no doubt, listened with their red ears out of a natural hospitality and courtesy, and afterward from curiosity or even interest, till at length there “were praying Indians,” and, as the General Court wrote to Cromwell, the “work is brought to this perfection that some of the Indians themselves can pray and prophesy in a comfortable manner.””
—Henry David Thoreau (1817–1862)