2 replies to this topic

[uglearner]

A PCR reaction requires 50 pMoles of primer (20 nucleotides in length) to be added to a 50 µl reaction. You have been supplied with an eppendorf (maximum capacity 1.5ml) which contains 66 µl of dried primer DNA. What do you to to end with 50 pMoles in your reaction?

Molecular weight of  1 nucleotide=660

How can I solve this ?

[protolder]

uglearner, on 06 February 2011 - 12:05 PM, said:

A PCR reaction requires 50 pMoles of primer (20 nucleotides in length) to be added to a 50 µl reaction. You have been supplied with an eppendorf (maximum capacity 1.5ml) which contains 66 µl of dried primer DNA. What do you to to end with 50 pMoles in your reaction?

Molecular weight of  1 nucleotide=660

How can I solve this ?

Hola, I think that your dried primer is 66 ug. If you disolve this in 100ul you have equivalent at 660ug/ml<>660mg/L, which dividing by 660 is a 1mM sol, wich has 1umol/ml <> 1 nmol/ul <>1000pmols /ul. Taking 1 ul of this + 19 ul of water (1/20dilution) you will have 50pmols/ul.So adding 1ul of this 1/20 sol. at the reaction tube andthe rest of components untill 50 ul you will have your reaction prepered. Good luck

[Maddie]

Look at the sheets that came with your primer, or on the tube itself. Most companies write how many nM or pM they gave you. When we receive our primers, we make a stock solution at 100uM (so we can simply add TLE in the 1.5ml tube itself )and then later on, we dilute the 100uM to 10uM.