I've joined a new lab, and my PI just told me that they have human fecal samples on swabs that have been stored at 4 degrees Celsius for about two years. She asked me if I thought it would still be worthwhile to try to measure cytokines in the samples. I have run tests before for stability of cytokine levels in human stool, but the longest I tested was about a week. Without question, the best way to store these samples would have been at -80, and every paper I've found so far reports storage at -80 or processing within a few days of collection. So that I can tell her I've exhausted all avenues, though, has anyone measured inflammatory factors like cytokines, CRP, NGAL, etc. in human stool that has not been frozen for an extended period of time? If so, what were the results like? Thank you!