Question: how much mgcl2 to add to pcr?
Answer: The optimum concentration of MgCl2 was within the range of 1.5 to 4.5 mM in the PCR mixtures for 154 of 200 random primers tested. The optimum concentration of MgCl2 for each primer was independent of the GC/AT ratio of the primer and the number of DNA band(s) amplified.