There are now a number of very definitive tests, most related to immune system profiling. Prof. Ron Davis has some good research and has shown that plasma from

There are now a number of very definitive tests, most related to immune system profiling. Prof. Ron Davis has some good research and has shown that plasma from someone with ME/CFS when combined with normal red blood cells will greatly diminish the ability for red blood cells to handle stress (pumping out salt).