Can you please help with this? I'm very confused and don't now how to start

Question

If the DNA concentration is 145.5 micrograms/mL afrter the concentration measurement and your PCR requires 10 ng/microliter of DNA for 20 microliters of PCR volume:

What is the volume of DNA that will need to be added to the PCR reaction mixture? (include all units)

Answer 1

You start with 145.5 micrograms / ml

You require only 10 ng / microliter

I will use standard abbreviations:

ug = microgram

ng = nanogram

ul = microliter

We want to have all of our units be the same and consistent.

You need 10 ng/ul and you want to make 20 ul, so you will need 200 ng (that is 10 ng/ul x 20 ul = 200 ng)

The original DNA is 145.5 ug/ml. We will convert that to ng/ul to be consistent.

145.5 ug/ml = 145.5 ng/ul

You need a total of 200 ng for the 20 ul of PCR, so how do we get 200 ng from a solution that is 145.5 ng/ul.

(x ul)(145.5 ng/ul) = 200 ng

x = 1.37 ul

So, the volume of DNA that you will need would be 1.37 microliters