Whatever the case, many organisms are going to convert that into something that would most definitely light such a test up, depending on how much of the substance were needed to cause a positive result. Its definitely not something I would rely on, that is for sure. But then, quite honestly, I think only someone with little to no experience collecting the mushrooms would even ask this (pls don't take that to be insulting, OP). Once you do some research and find out what fungus grows on what substrate, at what time of year, in your area, I think it should be rather obvious what you are looking for. It is best to have someone show you this in person, using many examples. But once you get it down, you should be ok. At least in the southern US, there are not very many types of mushrooms that you could confuse for P. cubensis or Pan. cyanescens. They are obvious from a combination of: shape, habitat, growth patterns, blueing/bruising, spore color, etc.