Aims. Fresh-frozen biopsies represent attractive samples for proteomic biomarker investigation, however, in large numbers logistics and archiving is difficult and expensive. Alternatively, FFPE samples are routinely prepared for pathological characterization and are abundantly available in tissue archives. The ability to conduct MS-based proteomic analyses of FFPE tissue opens new opportunities for clinical studies and biomarker discovery. Methods. We have used matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) to directly analyze peptides from FFPE sections by adapting the heat-induced antigen retrieval method. Trypsin and matrix deposition onto FFPE and fresh frozen biopsy specimens was carried out using the ImagePrep device (Bruker, Bremen) followed by subsequent MALDI MS analysis using a Bruker Autoflex Speed in profiling and imaging mode. Statistical analysis was done with ClinProTools 3.0. Each analysis was performed as an independent experiment to ensure statistical independence. We first investigated the reproducibility of the method by comparing the peak distribution of 5 different biopsies taken from the same patient. We then performed an on-tissue digestion experiment on a fresh-frozen tissue and on FFPE tissue taken from the same patient, to determine the comparability of these two types of samples. Results. Using ImagePrep, high-quality MALDI mass spectra and highspatial resolution ion images were obtained from fresh frozen and FFPE biopsies. The resulting MS spectra showed remarkably similar peptide profiles between fresh-frozen and FFPE tissues. Conclusions. Our results highlight the use of MALDI IMS technologym for the rapid detection of peptides in FFPE samples with high accuracy and reproducibility. This is of crucial importance and provides the basis for the introduction of MALDI IMS into routine histopathological practice.
Matrix-Assisted Laser desorption/ionization imaging mass spectrometry (MALDI IMS) for the analysis of FFPE biopsies. MALDI IMS Anwendung an Formalin-fi xiertem Gewebe
Casadonte R;
2013-01-01
Abstract
Aims. Fresh-frozen biopsies represent attractive samples for proteomic biomarker investigation, however, in large numbers logistics and archiving is difficult and expensive. Alternatively, FFPE samples are routinely prepared for pathological characterization and are abundantly available in tissue archives. The ability to conduct MS-based proteomic analyses of FFPE tissue opens new opportunities for clinical studies and biomarker discovery. Methods. We have used matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) to directly analyze peptides from FFPE sections by adapting the heat-induced antigen retrieval method. Trypsin and matrix deposition onto FFPE and fresh frozen biopsy specimens was carried out using the ImagePrep device (Bruker, Bremen) followed by subsequent MALDI MS analysis using a Bruker Autoflex Speed in profiling and imaging mode. Statistical analysis was done with ClinProTools 3.0. Each analysis was performed as an independent experiment to ensure statistical independence. We first investigated the reproducibility of the method by comparing the peak distribution of 5 different biopsies taken from the same patient. We then performed an on-tissue digestion experiment on a fresh-frozen tissue and on FFPE tissue taken from the same patient, to determine the comparability of these two types of samples. Results. Using ImagePrep, high-quality MALDI mass spectra and highspatial resolution ion images were obtained from fresh frozen and FFPE biopsies. The resulting MS spectra showed remarkably similar peptide profiles between fresh-frozen and FFPE tissues. Conclusions. Our results highlight the use of MALDI IMS technologym for the rapid detection of peptides in FFPE samples with high accuracy and reproducibility. This is of crucial importance and provides the basis for the introduction of MALDI IMS into routine histopathological practice.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
