Stool cultures for candida aren't reliable. Tartaric Acid in urine could be reliable if your overgrowth is big when you take the test. This test was developed by Dr. Shaw who direct Great Plain Lab since he is doing an effort to discover what cause autism. So far, the most reliable test is candida immunecomplexes. Guys, you dont need to have an active overgrowth to get a positive immuneglobulin IGG. This immuneglobulin remain high even months after the infection is under control. The only problem this test has is some people can test positive without an overgrowth and if you are immunesupressed , it may be negative. But since we all are looking for a positive result to confirm what we have, the test is ideal for us. I believe my immune system is working. I don't know if it is working perfect but my white blood count is ok plus some T cell tests. What I say is this... I got tested for H. pylori in blood (antibody) and the result was very high (positive) If I have candida overgrowth in my gut, what it couldn't show in an antibody test in blood. H. pylori lives in the gut and the blood antibody was present. So, you develop antibodies against H. pylori and against candida you don't develop them. I have read that immunecomplexes is the best we can take. If you are immune competent and candida is there, the test must be POSITIVE.