Table 2.

Analysis of LC/MS/MS data. Percent of false protein identifications for each sample.

Sample type	Buffer pH	Extraction Pressure	% False protein IDs*
Native, unfixed protein mixture	N/A	N/A	3.3 ± 0.6
Tissue surrogate	4	14.7 psi **	42 ± 4.0
Tissue surrogate	4	40,000 psi	7.8 ± 1.5
Tissue surrogate	8	14.7 psi	100
Tissue surrogate	8	40,000 psi	5.7 ± 1.1

^*Determined as percentage of proteins incorrectly identified for spectra for 2 technical replicates.

^**Atmospheric pressure. N/A=not applicable.