Acid rain is produced by volcanic eruptions. Acid rain has been shown to have adverse impacts on forests, freshwaters and soils, killing insect and aquatic life-forms, causing paint to peel, corrosion of steel structures such as bridges, and weathering of stone buildings and statues as well as having impacts on human health. "Acid rain" is a popular term referring to the deposition of a mixture from wet (rain, snow, sleet, fog, cloudwater, and dew) and dry (acidifying particles and gases) acidic components. Distilled water, once carbon dioxide is removed, has a neutral pH of 7. Liquids with a pH less than 7
Neutral red vital stain. Live cells incorporate neutral red into their lysosomes. As cells begin to die, their ability to incorporate neutral red diminishes. Thus, loss of neutral red uptake corresponds to loss of cell viability. It is also used to stain cell cultures for plate titration of viruses. Neutral red is added to some growth media for bacterial and cell cultures. It usually is available as a chloride salt. Neutral red acts as a pH indicator, changing from red to yellow between pH 6.8 and 8.0. Neutral red Neutral red (toluylene red, Basic Red 5, or C.I. 50040) is a eurhodin