Protein Loss Quantification of Abraded Virgin and Bleached Hair Using Bradford Assay

The study evaluated the Bradford assay as an alternative to the Lowry test for quantifying hair damage during combing or brushing by measuring protein loss. The Bradford method, which involves the binding of Coomassie Brilliant Blue G-250 to keratin, was found to be rapid, sensitive, and less prone to interference from common hair care ingredients compared to the Lowry procedure. Results indicated that virgin hair released significantly less protein (0.875 to 1.03 mg/g) than bleached hair (4.85 to 5.35 mg/g) during combing, demonstrating the greater susceptibility of bleached hair to protein loss. The method provided reproducible results with stable color development for up to one hour.