BCA protein assay compatibility.Thermo Fisher Pierce has recently introduced a new version of the classical Pierce BCA Protein assay compatible with reducing agents such as dithiothreitol (DTT), 2-merceptoethanol (BME), TCEP and other disulfide reducing agents [2].Compared to other methods BCA assay is one of the most sensitive (it can detect proteins at concentrations as low as 5 ug/mL).