<prompt> Cation used in PCR isCalciumLithiumMagnesiumSodium  <response>: All polymerases require divalent cations for their activity but some tend to function in buffers containing Mn2 as well, although a little less efficiently.dNTPs and oligonucleotides bind to Mg2 and therefore its concentration should exceed the molar concentration of phosphate groups that are contributed from both the dNTPs and primers.dNTPs bind in equimolar concentration with Mg2. 