Similar Datasets
Project description:We present FFPE-ATAC, a new ATAC-seq tool for chromatin accessibility profiling that decodes the chromatin accessibility from mouse FFPE tissue and clinical archived FFPE tissues. The FFPE-ATAC generates the high-quality chromatin accessibility profiles from clinical FFPE tissue sections with 5-20 µm thickness, and reveals the disease-associated regulatory elements in different types of FFPE archived tissue. FFPE-ATAC enables to decode the chromatin states regulating the gene regulation in the cancer and understand the epigenetic regulation in the translational studies.
2021-06-30 | GSE163306 | GEO
Project description:: A major challenge to the study of tumor DNA copy number (CN) in clinical specimens is the lack of appropriate fresh frozen samples and thus a dependence on Formalin-Fixed Paraffin Embedded (FFPE) banked samples, which typically have more extensive clinical follow up information. However, on most high density CN platforms, DNA from FFPE tissues generally underperforms or suffers high failure rates compared to fresh frozen samples because of DNA degradation and cross-linking. Molecular Inversion Probe (MIP) technology has been applied successfully to obtain high quality CN and genotype data from DNA isolated from cell lines and frozen tumor samples. Since the MIP probes require only a small (~40 bp) target binding site, we reasoned they may be well suited to assess FFPE samples. In this study, we successfully applied MIP technology with a panel of 50,000 markers to CN determination in FFPE samples. Using an input of 37 ng genomic DNA, we demonstrated high quali ty CN data with MIP technology from 93 FFPE samples from seven diverse collections. We found that the performance of FFPE DNA for CN determination was comparable to that of DNA obtained from matched frozen tumor, with only a modest loss in performance of DNA.
2009-02-18 | GSE14745 | GEO
Project description:A major challenge to the study of tumor DNA copy number (CN) in clinical specimens is the lack of appropriate fresh frozen samples and thus a dependence on Formalin-Fixed Paraffin Embedded (FFPE) banked samples, which typically have more extensive clinical follow up information. However, on most high density CN platforms, DNA from FFPE tissues generally underperforms or suffers high failure rates compared to fresh frozen samples because of DNA degradation and cross-linking. Molecular Inversion Probe (MIP) technology has been applied successfully to obtain high quality CN and genotype data from DNA isolated from cell lines and frozen tumor samples. Since the MIP probes require only a small (~40 bp) target binding site, we reasoned they may be well suited to assess FFPE samples. In this study, we successfully applied MIP technology with a panel of 50,000 markers to CN determination in FFPE samples. Using an input of 37 ng genomic DNA, we demonstrated high quali ty CN data with MIP technology from 93 FFPE samples from seven diverse collections. We found that the performance of FFPE DNA for CN determination was comparable to that of DNA obtained from matched frozen tumor, with only a modest loss in performance of DNA.
2009-02-18 | GSE14742 | GEO
Project description:A major challenge to the study of tumor DNA copy number (CN) in clinical specimens is the lack of appropriate fresh frozen samples and thus a dependence on Formalin-Fixed Paraffin Embedded (FFPE) banked samples, which typically have more extensive clinical follow up information. However, on most high density CN platforms, DNA from FFPE tissues generally underperforms or suffers high failure rates compared to fresh frozen samples because of DNA degradation and cross-linking. Molecular Inversion Probe (MIP) technology has been applied successfully to obtain high quality CN and genotype data from DNA isolated from cell lines and frozen tumor samples. Since the MIP probes require only a small (~40 bp) target binding site, we reasoned they may be well suited to assess FFPE samples. In this study, we successfully applied MIP technology with a panel of 50,000 markers to CN determination in FFPE samples. Using an input of 37 ng genomic DNA, we demonstrated high quality CN data with MIP technology from 93 FFPE samples from seven diverse collections. We found that the performance of FFPE DNA for CN determination was comparable to that of DNA obtained from matched frozen tumor, with only a modest loss in performance of DNA.
2009-02-18 | GSE14740 | GEO
Project description:The reliability of differential expression analysis on FFPE expression profiles from Affymetrix arrays is questionable, due to the wide range of percent-present values reported in studies which profiled FFPE samples on Affymetrix arrays. Moreover the validity of externally defined gene-modules in FFPE microarray expression profiles is unknown. Using eight breast cancer tumors with available frozen and FFPE samples, five sample-matched data sets were generated from different combination of Affymetrix arrays, amplification-and-labeling kit and sample preservation method. The reliability of differential expression analysis was investigated by developing de novo ER/HER2 pathway gene-modules from matched data sets and validating it on external data set using ROC analysis. Spearman's rank correlation coefficient of module scores between matched FFPE-frozen expression profiles was used to measure reliability of externally defined gene-modules in FFPE expression profiles. Independent of array/amplification-kit/sample preservation method used, de novo ER/HER2 gene-modules derived from all matching data sets showed similar prediction performance during independent validation (AUC range; ER: 0.92-0.95, HER2: 0.88-0.91), except for de novo HER2 gene-module derived from FFPE data set with 3'IVT kit (AUC: 0.67-0.72). Further not all gene-module based biological signals present in frozen expression profiles can be recovered from matching FFPE microarray expression profiles using the currently available FFPE specific sample preparation kits. The gene-module based biological signal extracted from FFPE RNA, using microarrays, may not be as reliable as that from their frozen counterpart, if the sample preparation protocol used with FFPE RNA failed to recover relevant genes involved in the biological signal.
2018-09-05 | GSE93337 | GEO
Project description:COMPARE Ring Trial 2019 on FFPE material
| PRJEB32130 | ENA
Project description:The reliability of differential expression analysis on FFPE expression profiles from Affymetrix arrays is questionable, due to the wide range of percent-present values reported in studies which profiled FFPE samples on Affymetrix arrays. Moreover the validity of externally defined gene-modules in FFPE microarray expression profiles is unknown. Using eight breast cancer tumors with available frozen and FFPE samples, five sample-matched data sets were generated from different combination of Affymetrix arrays, amplification-and-labeling kit and sample preservation method. The reliability of differential expression analysis was investigated by developing de novo ER/HER2 pathway gene-modules from matched data sets and validating it on external data set using ROC analysis. Spearman's rank correlation coefficient of module scores between matched FFPE-frozen expression profiles was used to measure reliability of externally defined gene-modules in FFPE expression profiles. Independent of array/amplification-kit/sample preservation method used, de novo ER/HER2 gene-modules derived from all matching data sets showed similar prediction performance during independent validation (AUC range; ER: 0.92-0.95, HER2: 0.88-0.91), except for de novo HER2 gene-module derived from FFPE data set with 3'IVT kit (AUC: 0.67-0.72). Further not all gene-module based biological signals present in frozen expression profiles can be recovered from matching FFPE microarray expression profiles using the currently available FFPE specific sample preparation kits. The gene-module based biological signal extracted from FFPE RNA, using microarrays, may not be as reliable as that from their frozen counterpart, if the sample preparation protocol used with FFPE RNA failed to recover relevant genes involved in the biological signal.
2018-09-05 | GSE93336 | GEO
Project description:The study aimed to apply 95GC, originally developed using fresh‑frozen (FF) tissues, to formalin‑fixed paraffin‑embedded (FFPE) tissues, because FFPE tissues are routinely prepared and are readily available. Although we previously reported the applicability of 72GC to FFPE tissues (DOI: 10.1016/j.clbc.2013.11.006), the present study aimed to improve the accuracy of 95GC for FFPE tissues using the reference robust multiarray average (refRMA) method, optimized for FFPE tissues. Therefore, a 95GC RS (Recurrence Score) was first developed and then the accuracy of the newly developed 95GC algorithm for FFPE tissues was evaluated using the 95GC RS. These 14 pairs of FF and FFPE data are included in the concordance analysis of 95GC high/low results between FF and FFPE (Figure 3B). J05 was created in a form more suited to the actual clinical setting, such as leaving the postoperative samples for 4 hours before immersing them in formalin. A long time passed, and now it is unclear how these 14 cases were distributed among the analysis. *Note: This old data has been updated multiple times by the other members. Then, there are some differences from the original paper and unclear points still remain. Therefore, do not use it for formal analysis aimed at public insurance coverage etc. This is for research purposes only. Please cite this paper when writing a new paper. PMID: 31638234 DOI: 10.3892/or.2019.7358
2023-07-11 | GSE236723 | GEO