Posted 5/15/2009 1:10 AM (GMT -7)
PCR tests look for actual Lyme DNA
The WesternBlot tests look for antibodies (IgM and IgG) that your immune system has generated to fight the Lyme bacteria
Since Lyme prefers tissue rather than blood, the PCR test may be less helpful. However, PCR results that are positive are nearly irrefutable, and more likely to be accepted by IDSA-following MD's.
If I were trying to save money but at the same time wanted to figure out if I had Lyme, I'd go for the IgG and IgM WesternBlot tests (188 & 189) first. Then, depending on the results and the attitude of the doctor, I might or might not persue further tests.