Evans Blue

Evans Blue, also known as Direct Blue 53 or T-1824, is a dye that has been widely used in medical and scientific research. It is named after Herbert McLean Evans, a prominent American anatomist and embryologist.

History

Evans Blue was first synthesized in the late 19th century and has been used in various fields of research since the early 20th century. It was named after Herbert McLean Evans, who used the dye in his pioneering studies of the circulatory system.

Properties and Uses

Evans Blue is a diazo dye, meaning it contains two nitrogen atoms connected by a double bond. It is known for its intense blue color and its ability to bind to serum albumin, a protein found in blood plasma. This property makes it useful in a variety of scientific and medical applications.

In medicine, Evans Blue is used as a diagnostic tool to measure blood volume and to detect protein leakage in the blood vessels. It is also used in research to study the blood-brain barrier, a protective barrier that prevents substances in the blood from entering the brain.

In biology, Evans Blue is used to stain cells and tissues for microscopic examination. It is particularly useful for staining necrotic (dead) cells, as it is excluded by live cells but can penetrate and stain dead cells.

Safety and Toxicity

While Evans Blue is generally considered safe for use in research, it can be toxic in large amounts. It has been shown to cause skin irritation and eye irritation in humans, and can be harmful if swallowed or inhaled. It is classified as a hazardous substance under the Occupational Safety and Health Administration's Hazard Communication Standard.

See Also

• Coomassie Brilliant Blue
• Trypan Blue
• Sudan III