Primer Resuspensions and Dilutions: ---Resuspension of newly arrived primers: First, spin all tubes to ensure that any dried pellets are not trapped in the caps. Dissolve fresh primer with the 10X volume of TE as its concentration: For example, if tube contains 25 nmoles of primer add 250 ul of TE. This will give you a concentration of 0.0001 M or 0.1 mM (25 nmoles/L) (X moles/250 x 10-6 L) = .0001 mole/L = 0.0001 M = 0.1 mM = 100 µM This is your ‘stock’ primer. ---Dilution of prepare ‘working’ primer solution for use: Dilute this stock 1:10, to give a concentration of 10 M For example, if you want 200 L of a 10 M primer, you would dilute 20 L of stock primer in 180 L of water or TLE. C1 x V1 = C2 x V2 (100 M * X L) = (10 M * 200 L), solve for X X = (10 M * 200 L)/100 M X = 20 L of primer stock dissolved in 180 L of water or TLE for a final volume of 200 L. ---From this, use ~0.5-1 l in a typical PCR reaction. This will give you a final concentration of 5-10 pmoles in a PCR reaction. (Because 1 L of 10 M = 10 moles/10-6 L = 0.00001 mole/l = 10 pmol/l)