How would you prepare 1 liter of 1X Tris Glycine running buffer from a 10X stock solution.
The correct answer and explanation is:
To prepare 1 liter of 1X Tris Glycine running buffer from a 10X stock solution, you need to dilute the 10X stock to achieve a 1X concentration. The dilution factor is determined by dividing the final concentration (1X) by the stock concentration (10X).
- Calculation for dilution:
Since the 10X stock solution needs to be diluted to 1X, the dilution factor is 10. This means you need 1 part of the 10X solution for every 9 parts of water. - Volume of stock needed:
To prepare 1 liter (1000 mL) of the 1X solution, use the following formula:
Volume of stock=Desired volumeDilution factor=1000 mL10=100 mL\text{Volume of stock} = \frac{\text{Desired volume}}{\text{Dilution factor}} = \frac{1000 \, \text{mL}}{10} = 100 \, \text{mL}
So, you will need 100 mL of the 10X Tris Glycine stock solution. - Volume of water to add:
After adding 100 mL of the 10X stock solution, you need to add enough water to bring the final volume to 1 liter (1000 mL). Therefore, subtract the volume of the stock solution from the total desired volume:
Volume of water=1000 mL−100 mL=900 mL\text{Volume of water} = 1000 \, \text{mL} – 100 \, \text{mL} = 900 \, \text{mL}
So, you need to add 900 mL of deionized or distilled water. - Procedure:
- Measure 100 mL of the 10X Tris Glycine stock solution.
- Add the 100 mL to a 1-liter container or beaker.
- Add 900 mL of deionized water to the container.
- Mix thoroughly to ensure the solution is homogeneous.
- Final Solution:
You will have 1 liter of 1X Tris Glycine running buffer, which is now ready for use in gel electrophoresis or other applications that require this buffer.
The purpose of Tris Glycine buffer in electrophoresis is to provide a stable pH environment and conduct electricity, allowing for the separation of proteins or nucleic acids. The 10X stock is used for convenience and longer shelf life, as it is more concentrated and can be easily diluted for immediate use.