Bromophenol Blue is an organic compound with the chemical formula C₁₉H₁₀Br₄O₅S and CAS Number 115-39-9. It is typically supplied as a dark red, reddish-purple, or purple powder, depending on the product grade and supplier specifications. Its colour changes from yellow in more acidic conditions to blue-violet in less acidic or more alkaline conditions, with a transition range of approximately pH 3.0 to 4.6.

Bromophenol Blue is valued for its colour-changing properties and suitability for a range of laboratory procedures. Common applications include acid-base indicator solutions, pH-related experiments, analytical chemistry, biochemical research, and electrophoresis, where it may be used as a tracking dye to monitor the progress of sample migration.

In biochemical and molecular biology laboratories, Bromophenol Blue is frequently incorporated into sample loading buffers for gel electrophoresis. Its visible colour helps researchers track the movement of samples through the gel during the separation process.

Its established indicator properties make Bromophenol Blue useful in educational laboratories, analytical testing, and scientific research. The appropriate grade and purity should be selected according to the intended application, particularly when used in specialised biochemical procedures.

KSFE Malaysia supplies laboratory chemicals and scientific products for research institutions, educational facilities, and general laboratory applications.

Safety Note: Handle Bromophenol Blue in accordance with the product label and supplier's safety data sheet (SDS). Avoid inhalation of dust and contact with the eyes and skin. Use appropriate personal protective equipment and handle the powder carefully to minimise dust generation. Store the product in a tightly closed container under the recommended conditions and follow the supplier's instructions for handling, storage, and disposal.