Optical density measured from an increased concentration of Poly(lactic-co-glycolic acid) (PLGA) following test on bicinchoninic acid (BCA) assayThe bicinchoninic acid (BCA) assay is a colorimetric assay that measures protein concentration in a sample based on a chemical reaction that causes a change of colour. Peptide bonds and certain amino acids such as cysteine, tryptophan, and tyrosine enable the reduction of cupric ions (Cu2+) to cuprous ions (Cu+) in an alkaline medium, also known as the biuret reaction. The resulting cuprous ions then react with the sodium of two bicinchoninic acids to generate a purple colour, the purple complexThe dataset above presents the optical density from the purple complex measured from an increased concentration of Poly(lactic-co-glycolic acid) (PLGA) particles.