User:Dhea Patel/Notebook/Experimental Biological Chemistry Notebook/2012/08/29

Objective

• to make stock solutions of HAuCl₄ and BSA.
• to make 14 differently concentrated HAuCl₄ and BSA mixtures.

Description

1. Calculations were made to determine how much HAuCl₄ was required to make 25mL of 10mM stock solution.
2. Calculations were made to determine how much BSA was required to make 10mL of 15μM stock solution.
3. The appropriate amounts of HAuCl₄ and BSA were massed separately and added to separate test tubes.
4. The appropriate amount of H₂O were added to each test tube. (25mL to the HAuCl₄ test tube and 10mL to the BSA test tube.)
5. The test tubes were covered with parafilm.
6. The test tube containing HAuCl₄ was also completely covered in aluminum foil.
7. Then, using the m₁v₁=m₂v₂ equation, the amount of each stock solution required to make 4mL mixtures with the Au³⁺/BSA concentration ratio of 60μM, 80μM, 100μM, 120μM, 128μM, 130μM, 132μM, 133μM, 134μM, 136μM, 138μM, 140μM, 160μM, and 170μM.
8. After the amounts of each stock solution was determined, the appropriate amounts of HAuCl₄, BSA, and H₂O were added to each test tube.
9. The test tubes were capped, covered in aluminum foil, labeled, and placed in the oven at 85°C at 4 hours.

Data and Calculations

• HAuCl₄ Stock

  FW HAuCl4: 393.83 g/mol
  Theoretical Concentration of Stock: 10mM
  Volume of Stock: 25mL
  Theoretical Mass:
        25mL × 10-3 L/mL × 10mM × 10-3 mol/mmol × 393.83 g/mol = 0.0985 g HAuCl4
  Measured Mass: 0.0971 g HAuCl4
  Calculated Concentration: 9862 μM
        0.0971g × (1/393.83 g/mol) × (1/25E-3 L) × 106 μM/mol = 9862 μM 

• BSA Stock

FW BSA: 66430 g/mol
  Theoretical Concentration of Stock: 15μM
  Volume of Stock: 10mL
  Theoretical Mass:
        10mL × 10-3 L/mL × 15μM × 10-6 mol/mmol × 66430 g/mol = 0.00996 g BSA
  Measured Mass: 0.0105 g BSA
  Calculated Concentration: 15.806 μM
        0.0105g × (1/66430 g/mol) × (1/10E-3 L) × 106 μM/mol = 15.806 μM 

• Volumes of HAuCl₄, BSA, H₂ required for various 4mL HAuCl₄/BSA mixtures

Notes

• The stocks were made with the incorrect concentrations, so the reaction did not occur properly.
• The stocks were made without the parafilm protection on the spatula.

Image of the Solutions Produced

• All the solutions from August 29, ranging from 60μM to 170μM Au/BSA concentration. The solution was made without the parafilmed spatula. THe solution spent 4 hours in a 85°C oven.