Figure 4: Quality comparison of MS profiles of native protein mixture and tissue surrogate extracts. FFPE tissue surrogates were heated in 50 mM Tris, pH 8+2% SDS at either elevated pressure (40,000 psi) or atmospheric pressure. The extracts were analyzed by LC/MS and the MS traces of each tissue surrogate extract were compared to the native, unfixed protein mixture. A) native, unfixed tissue surrogate mixture; B) FFPE tissue surrogate retrieved at 40,000 psi; C) FFPE tissue surrogate retrieved at atmospheric pressure (14.7 psi).