A Western Blot is a blood test done for Lyme Disease. Usually it is sent to a lab in California called IgeneX. They test for 14 different bands on the IgG which means recent infection and IgM which is past infection. There are 6 Lyme specific bands and if they show up with a + then you have been exposed to Lyme. That is how I found out I had Lyme after 2 years of the doctors telling me there was nothing wrong with me! Any other questions I will be happy to answer them.