Hi Zach, this is Ali. Sorry it took me so long to review your article, but I had to study for an exam I just took today (Dec. 17th). Your article gives a good overview of the aqueous two-phase separation technique, but I think you should delve a little deeper into the thermodynamics of the separation. I already know the reasons why polymer/polymer phases are immiscible. However, I don't believe anyone without knowledge of polymers will know those reasons, so it would be good if you post a thermodynamic explanation of polymer immiscibility. Also, it would be great if you could clarify the thermodynamics of protein partitioning between two aqueous phases. For instance, is the partitioning of this system similar to the partitioning of regular solvent extraction? Once again, apologies for the long wait.