Isolation of DNA after extraction of RNA to detect the presence of Borrelia burgdorferi and expression of host cellular genes from the same tissue sample

We are investigating the neuropathogenesis of Lyme disease caused by Borrelia burgdorferi in a nonhuman primate model. In the past, two separate pieces of tissue had to be used when both analyzing for the presence of the spirochete and examining the host response to infection. We have modified a procedure to purify DNA from the same sample after the extraction of RNA. The remaining material containing the DNA was precipitated, and residual organic reagent was removed prior to deproteinization and extraction of the DNA. This procedure now allows us to both assay for the presence of the Lyme microorganism and analyze the host response in the same tissue preparation.