Micro BCA Protein Assay Protocol (Pierce)

Detection range: 0.5-20 mg/ml

Materials

Pierce Micro BCA Protein Assay Kit, Catalog # 23235

Methods

• 1. Dilute 2 mg/ml BSA stock solution (provided in 1 ml ampules) according to chart below, preferably with same diluent as your sample.

  2. Pipet 1 ml of each standard and sample in 15 ml centrifuge tubes. Blank tubes should consist of 1 ml of diluent.

  3. Prepare a working solution of BCA Reagents, assuming 1 ml working solution per sample or standard. Add 25 parts Reagent MA to 24 parts Reagent MB and 1 part Reagent MC (25:24:1 Reagent MA:MB:MC) and mix well. The working solution will be a clear-green color and is stable for several days at room temperature in the dark.

  4. Add 1 ml of the working solution to each centrifuge tube containing samples/standards.

  5. Incubate the tubes at the 60°C for 1 hour.

  6. Cool all tubes to room temperature on shaker plate.

  7. Measure the absorbance at 562 nm on the UV-Vis. Zero the UV-Vis using diH₂O, and read all samples within 10 minutes. The BCA reaction has no true end point, so color development continues even at room temperature.

Standard dilutions: