Peptidomics is the complete quantitative and qualitative analysis of endogenous peptides in a biological sample. The total protein content is an important analytical task for peptidomics as it allows for the determination of the sample size required for such analysis. One particular method that is used for the quantitation of total protein is the BCA method. The BCA method uses the reaction of two cuprous ions with a bicinchoninic acid (BCA) molecule to produce a purple colored product. In addition, the BCA/copper complex absorbs at a wavelength of 562 nm, and this wavelength is used to detect the absorption of the sample. For this particular project, the Thermo ScientificTM Micro BCATM Protein Assay Kit was used to assay the total protein in frozen, pulverized mouse brain tissue. The kit used diluted protein standards and concentrated reagents along with a period of incubation at 37°C to produce a colorimetric protein assay in a 384-well plate. Using the Epoch microplate spectrophotometer, a wavelength of 562 nm was selected to interact with the samples, and the number of photons absorbed by the samples was detected by the photometer. The data was collected by the Gen5 software, and a standard curve was prepared by plotting the absorbance against concentration. This curve was used to determine the concentration of protein in the unknown mouse brain samples.UIUC Neuroproteomics and Neurometabolomics Center on Cell-Cell SignalingP30DA018310Ope
