Hi New UK. The labs do use fixatives. I don't think they use microscopy. I have made a positive ID myself. The cryptosporidium and cyclospora were a surprise to me. And the oocyts were very plentiful. There is NOOO way the labs could have missed them. That is unless they used chemical testing which could show false negatives. I think there is more going on here. I will have proof soon, because the microscope I have on order has full photographic capabilities. The symptoms are in-line with this parasite. ------------I have thought about the urine therapy, it does have scientific validity. Maybe I will try an experiment in vitro. Shroom