Primer DNA Stock Solution Preparation: How Much Sterile Diluent Needed?

Question:

You've received primer DNA in a tube from the primer company. The tube has 20 nmole of primer DNA. In order to make 200 pmole/μL of primer DNA stock solution, how much of sterile diluent do you need?

Answer:

To prepare a 200 pmole/μL primer DNA stock solution from the 20 nmole of primer DNA provided, you will need to dilute it with a sterile diluent. The amount of sterile diluent needed can be calculated as follows:

First, determine the final volume of the stock solution you want to prepare. Since you want 200 pmole of primer DNA per μL and you have a total of 20 nmole of primer DNA, the total volume should be:

Vf = Total amount of primer DNA / Desired concentration

Vf = 20,000 pmole / 200 pmole/μL = 100 μL

Therefore, you need to make a total volume of 100 μL for your stock solution.

Next, to find out how much of the total volume is the sterile diluent, subtract the volume of primer DNA from the total volume:

Vd = Vf - Vp = 100 μL - 20 μL = 80 μL

So, you will need 80 μL of sterile diluent to make a 200 pmole/μL primer DNA stock solution from the 20 nmole of primer DNA provided.