I hard to explain so drew it.
As you know, PCI solution(phenol:chloroform:Isoamylalcohol 25:24:1) have a two layers. PCI is lower layer, and there are solution located upper.
what's this? I founded about this, someone said Tris(50mM, 10mM, 100mM) or Isoamylalcohol, but I don't agree Isoamylalcohol because phenol and chloroform, Isoamylalcohol can mixed because phenol and chloroform are organic solvent, and ethanol can mix with organic solvent. (and Isoamylalcohol have non-polar parts)
Then My question Is Two:
1. what solution in upper layer of Phenol:chloroform:isoamylalcohol 25:24:1?
2. if that solution is Tris, It role just prevent oxidation of phenol? never role of buffering agent? or it works by buffering agent for prevent oxidation of phenol?