# Resuspending primers calculation - (Jul/11/2013 )

I'm having problems trying to understand de chemestry in resuspending primers. I know I can use online calculators, and I have the general formula like multiply the initial (dry) concentration x10 and get a final concentration of 100 ul/L or

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Usually primers (oligos) come in lyphilized powder with the amount (mass) indicated on the tube, for example, 4.9 nmol. We usually reconstitute the primer to make a 100 uM/L stock solution, we will need to add 49 ul TE buffer to the tube (4.9 nM/49 ul = 100 um/L). So if you know the amount of the primer from the tube, it is easy to determine how much solvent is needed without any calculation.

To put it in a simple way, if you have

be careful with nomenclature. uM=umol/L. uM/L is, at best, redundant, at worst, meaningless.

Thank you very much for your answers. My confusion is with nomenclature indeed.

We** multiply nmol of primers by 50** to find the micro liter of water that should be added to them.

for example:

primer GAPDH-F nMol is 20

so multiply it by 50=> **20*50= 1000 **

now add 1000 microlitter of clean water to it and mix.

now 1micro litter is enough for 10 to 50 micro litter of pcr reaction.