I had been tested years ago by the initial ELISA screening test and it was negative. When a number of people on antoher forum began testing positive, I decided to ask to be tested again. One of my doctors had me tested by IGenex Western blot IgG/IgM for Borrelia only. The cost was ~ $200-250 - out of pocket. He said I already fit the clinical diagnosis. When that test came back positive on IgG but "negative" on IgM, he felt I needed to be tested for co-infections. That testing cost quite a bit more but it demonstrated that I had Babesia and Anaplasmosis. I had never been treated for any of these and I had all the symptoms. Many other things showed up as well - HHV-6, EBV, Mycoplasma, and Chlamydia. I just learned of an LLMD in California, Dr. Stephen Harris. He has a chapter in the book Insights into Lyme Disease Treatments that you can read here : http://www.lymebook.com/steven-harris It has a lot of good information.