Rose bengal is a chemical compound used as a stain for identifying certain types of tissues while screening for disease and other medical problems. It also has a number of other uses in medical research and as of 2010, was in development as a cancer treatment for certain types of melanoma and breast cancer. This compound is sold through scientific supply companies, particularly those specializing in supplying materials to medical researchers.
The compound is a derivative of fluorescein. Depending on how it is handled, it can fluoresce with red to blue coloration in certain environments. One common use for rose bengal is in ophthalmology, where eye drops are used to check for damaged cells in the eye during screening for cancers and other eye disorders. The rose bengal will highlight dead or damaged cells, acting like a red flag for a physician.
It is also used in liver function tests used to screen for liver cancer. In research, rose bengal is utilized in various experimental activities where a stain is necessary or useful. Its fluorescent chemical properties can make it valuable in a wide variety of experiments. Exposing it to light it reacts to can also be used to trigger chemical reactions inside the body of a test subject, as seen in the development of experimental stitches formed by collagen fibers activated when rose bengal fluoresces under light.
In medical research, certain types of agar plates may be prepared with this compound because it can inhibit the growth of some forms of bacteria. When these bacteria are undesirable on a plate, using agar designed to repel their growth will reduce the risks of contamination. In addition, rose bengal is used to stain specimens such as planktonic organisms so they can be viewed more clearly under microscopic magnification. Using stains highlights physical structures, including very small ones that are normally extremely hard to see.
When working with stains, it is important to follow directions for their use. They are not suitable for all applications and using the wrong stain can ruin a specimen or test, or cloud results and make them less meaningful. There are specific protocols in use for analysis of specimens and medical tests involving the use of stains and other compounds. These protocols are designed to yield consistent, stable results when they are followed properly. It is especially important to be alert to any safety warnings listed in a protocol, including warnings about wearing eye protection and taking other measures to reduce the risk of injuries.