Please show me step by step in detail with all conversions needed, how to do the
ID: 537130 • Letter: P
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Please show me step by step in detail with all conversions needed, how to do these practice problems. I need to master these to prepare for a Harvard Internship, yet I have never seen these type problems before. Thank you so much! 6. How do you make 1x TBs Tween (Tris-Buffered Saline with Tween) from 10 x stock? And how about 5% milk in TBS-T of dry milk powder? 7. You have 1 M NaoH stock solution. How do you make 25 mM solution? 8. You have 0.5 M EDTA stock solution. How do you make 2 mM solution? 9. How do you make 0.2% Ponceau red in 2 acetic acid? You have 50% stock solution of acetic acid. 10. You are doing immunoprecipitation, and you need elution buffer that contains 1x reducing agent and 1x sample buffer. How do you prepare 30 ul of elution buffer with reducing sample buffer? You will have 10x reducing agent, 4x sample buffer, and your elution buffer is 50 mM glycine.Explanation / Answer
6a) We have a 10X buffer solution of TBS-T as stock and we need to make a 1X buffer solution. To prepare the solution, we need to dilute.
The dilution factor is given as (concentration of stock solution)/(concentration of desired solution) = (10X)/(1X) = 10.
This will simply mean that we need to dilute the stock solution 10 times. As an example, we will take 1 mL of 10X solution and dilute the same to 10 mL by adding deionized water to prepare a 1X solution.
b) We will assume that dry milk is 100% pure and we want to prepare a solution contain 5% dry milk. Again, we shall use a dilution factor.
The dilution factor is given as (concentration of stock solution)/(concentration of desired solution) = (100%)/(5%) = 20; i.e, we will need to dilute 20 times. We shall have to take 5 mL of 100% milk powder and dilute to 100 mL by adding deionized water.
7) The stock solution is 1 M; the desired concentration is 25 mM = (25 mM)*(1 M/1000 mM) = 0.025 M.
The dilution factor is (1 M)/(0.025 M) = 40, i.e, we have to dilute the stock solution by 40 times. This simply means that we take 2.5 mL of the stock solution and dilute by adding water to the 100 mL mark in a volumetric flask.
8) The stock solution is 0.5 M and the desired concentration is 2 mM = (2 mM)*(1 M/1000 mM) = 0.002 M.
The dilution factor is (0.5 M)/(0.002 M) = 250, i.e, we have to dilute the stock solution 250 times. Therefore, we can take 0.4 mL of the stock solution and dilute by adding water to the 100 mL mark.
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