Measurement of Protein Concentration

Overview

Teaching: 45 min
Exercises: 180 min

Questions

• How is concentration of protein in solution measured?

Objectives

• Students will identify factors that must be considered when choosing an appropriate assay for determination of protein concentration.

• Students will prepare standard solutions of a known protein to create a standard curve.

• Students will interpret absorbance measurements to determine the concentration of a protein solution.

• Students will be able to convert protein concentration between mg/mL and M.

• Students will explain the advantages of a linear standard curve vs. a nonlinear curve.

• Students will adjust their unknown protein concentrations to make measurements within the effective range of the standard curve.

The determination of protein concentration is an essential skill for biochemists. In earlier BASIL modules, students learned how to express and purify enzymes of unknown function. Determination of protein concentration by a dye-binding assay will enable students to characterize their enzymes in later modules. In the process students will also gain practice with accuracy and precision in pipetting, and data analysis. At the end of this module, students will have gained both practical and analytical skills that will prepare them for future lab work.

Module Resources

Download student module here

Key Points

• Measuring protein concentration is important for determining protein purification yield and amounts to use in further analyses.