STANDARD OPERATING PROCEDURE http://proteomics.cancer.gov M-101.1 Page 1 of 3 STANDARD OPERATING PROCEDURE Title: Protein concentration measurements using Bio-Rad protein assay kit SOP#: M-101 Version #: 1 Author: A. Stephen / G. Whiteley Date Approved: Feb. 6, 2009 Date Modified: 1. PURPOSE This procedure is to be used for the determination of the protein concentration. 2. SCOPE This document describes the procedure for measuring protein concentration of a sample. 3. RESPONSIBILITIES It is the responsibility of the person(s) performing this test to be familiar with lab safety procedures and to have basic laboratory skills. The interpretation of results must be done by a person trained in the procedure and familiar with such interpretation. 4. EQUIPMENT Perkin Elmer Lambda20 spectrophotometer 5. MATERIALS Polystyrene semi-microcuvettes; Sarstedt Cat. # 67.742 Parafilm 6. REAGENTS Protein to be tested BioRad Protein Assay concentrated dye reagent; BioRad Cat. #500- 0006 Bovine Serum Albumin (BSA) protein standard; Bio-Rad Cat. #500- 0007 http://proteomics.cancer.gov M-101.1 Page 2 of 3 7. PROCEDURE 7.1. Preparation of BSA standard curve 7.1.1. Take vial of lyophilized BSA standard from BioRad and reconstitute using Milli-Q water to a final concentration of 8mg/ml. 7.1.2. This material is stored in aliquots of 100l at –20oC. 7.1.3. Take 37.5l of the 8mg/ml stock of BSA standard and add 12.5l of milli-Q water for a final volume of 50l and a concentration of 6mg/ml. 7.1.4. Take 25l of the 8mg/ml stock of BSA standard and add 25l of milli-Q water for a final volume of 50l and a concentration of 4mg/ml. 7.1.5. Take 12.5l of the 8mg/ml stock of BSA standard and add 37.5l of milli-Q water for a final volume of 50l and a concentration of 2mg/ml. 7.2. Dilution of unknown protein and BSA standards 7.2.1. Add 800l of milli-Q water into 1ml semi-microcuvettes.