⿿Comparing the proteome of snap frozen, RNAlater preserved, and formalin-fixed paraffin-embedded human tissue samples

Large biobanks exist worldwide containing formalin-fixed, paraffin-embedded samples and samples stored in RNAlater. However, the impact of tissue preservation on the result of a quantative proteome analysis remains poorly described. Human colon mucosal biopsies were extracted from the sigmoideum and either immediately frozen, stabilized in RNAlater, or stabilized by formalin-fixation. In one set of biopsies, formalin stabilization was delayed for 30 min. The protein content of the samples was characterized by high throughput quantitative proteomics. We were able to identify a similar high number of proteins in the samples regardless of preservation method, with only minor differences in protein quantitation.