I'm trying to synthesis a hydroscopic peptide using a microwave assisted solid phase peptide synthesiser. I'm using an already optimised cleavage process, the issue arises after precipitating the peptide in -20 degrees diethyl ether. The precipitated peptide is then centrifuged at 3500rpm for 5mins during which my problem arises. After centrifugation I am left with a highly condensed, sticky, gel-like peptide mass that cannot be resuspended in diethyl ether despite sonification, etc. When left to dry out overnight the sticky gel-like nature persists and is incredibly difficult to weigh out/use etc. My predecessor would be left with a solid, dry pellet and is also confused as to why i'm not having the same result. I have resuspended the pellets in deionised water and freeze dried them but they quickly revert back into the unusable 'gel-like' state when removed from the freeze dryer. Any explanations/suggestions/solutions would be most helpful.