Bicinchoninic acid

The molecule consists of a pair of quinoline rings, each bearing a carboxylic acid group.

Its sodium salt forms a purple complex with cuprous ions.

[1][2][3] Bicinchoninic acid is most commonly employed in the bicinchoninic acid (BCA) assay, which is used to determine the total concentration of protein in a solution.

Bicinchoninic acid is used to detect the presence of cuprous ions, due to its purple coloration via a biuret reaction.

In this assay, two molecules of bicinchoninic acid chelate a single Cu+ ion, forming a purple water-soluble complex that strongly absorbs light at 562 nm.

NFPA 704 four-colored diamond Health 1: Exposure would cause irritation but only minor residual injury. E.g. turpentine Flammability (red): no hazard code Instability (yellow): no hazard code Special hazards (white): no code