# primer dilutions - (Apr/23/2012 )

hello,

please, can someone help :

I have:

F primer @ 100uM

R primer @ 100uM

2uL taken from each and placed into 8ul water, to make 10uL final volume primer mix. Each primer is (2/10)*100 = 20uM in the mix.

How to calculate the concentration of the mix? Will it be (4/10)*200uM = 80uM or (4/10)*100uM = 40uM

if I have :

F primer @ 100uM

R primer @ 100uM

i add 10uL of each into a new tube and mix. Then I will have F and R primer each at 50uM in the mix. The primer mix F/R is 100uM. Is that right?

If I have:

10uM F/R primer mix, is it possible to determine the concentration of F and R in the mix, is it simply 5uM each?

Right. For each primer, the concentration is 50 uM, for the total oligos, the concentration is still 100 uM.

Yes, the concentration for each is 5 uM.

Hi pcrman,

thanks. So is the first one, 40uM then?

I am a little confused about your first question, you said to take 2 ul from each and add to 8 ul. then the total will be 12 ul.

I assume you mean take 1 ul from each and add to 8 ul so the total will be 10 ul. If that is the case, the final concentration for each oligo will be 10 uM and the total oligo concentration will be 20 uM.

yes that is what i meant. thank you pcrman.