Bradford Stock Solution
- This solution is mainly used to determine the concentration of proteins in solution.
- The principle of detection is based on the formation of a complex between the dye, Brilliant Blue G, and proteins in solution.
- The protein dye complex causes a shift in the absorption maximum of the dye from 465 to 595 nm. The amount of absorption is proportional to the protein present.
- The Bradford Reagent requires no dilution and is suitable for micro, multiwell plate, and standard assays.
- This solution also compatible with reducing agents which are often used to stabilize proteins in solution.
- This solution is consist of t consists of Brilliant Blue G in phosphoric acid and methanol.
- Bradford Stock Solution is stable at 2–8 °C in an unopened container for at least 1 year.
Preparation of Bradford Stock Solution
To prepare 1L of Bradford Stock Solution, the following components are required;
| Component | Amount | Concentration |
| Ethanol (95%) (mw: 46.07 g/mol) | 333 mL | 31.67 % |
| Phosphoric acid (88%) (mw: 58.4 g/mol) | 667 mL | 58.67 % |
| Coomassie Brilliant Blue (mw: 825.97 g/mol) | 1.16 g | 1.41 M |
Procedure
- Prepare 0 mL of distilled water in a suitable container.
- Add 333 mL of Ethanol (95%) to the solution.
- Add 667 mL of Phosphoric acid (88%) to the solution.
- Add 1.16 g of Coomassie Brilliant Blue to the solution.
- Add distilled water until volume is 1 L.
References
- “Bradford Stock Solution Preparation.” AAT Bioquest, Inc, 04 May. 2021, https://www.aatbio.com/resources/buffer-preparations-and-recipes/bradford-stock-solution.
- https://www.sigmaaldrich.com/content/dam/sigma-aldrich/docs/Sigma/Bulletin/b6916bul.pdf
