(A) Representative Western blot of cell supernatants derived from HepG2 cells exposed to heat, freeze/thaw or detergent (2% Triton X-100) demonstrating the release of mitochondrial (TFAM, ND1, ND6) and nuclear (HMGB1) proteins. (B) Significant monocyte IL-8 release was observed 6 hrs after treatment with equal supernatant volumes (50 μl) derived from freeze/thaw, or heat-treated HepG2 cells (∼107 cells/ml) compared to matching untreated preparations (*p<0.05, compared to untreated Control). The results were compared to spontaneous release of IL-8 from monocytes in culture medium.