Figure 2: Absence of HSV DNA from normal heart tissues. HSV and IFN-γ PCR in representative cases with normal heart tissues. PCR. M: 100 bp molecular marker (New England Biolabs), 1 and 7: positive control (blood sample), 2–6: normal heart tissues, and 8: negative control (distilled water). IFN-γ was used to assess the quality and quantity of the examined DNA.