23953f5e-36d8-4582-b87d-df538a59af22 - samples
Ontology highlight
ABSTRACT:
PROVIDER: EGAD00001007686 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:Samples encompass primary colorectal tumors or metastasis of 75 patients, collected by Medical Pathologists from surgically removed specimens. Tissues were embedded in optimal cutting temperature (OCT) medium, snapshot frozen in liquid nitrogen within 40 minutes of collection and preserved at -80ºC. Samples were collected between June 2010 and October 2017 as part of a prospective biobanking project.
| EGAD00001009506 | EGA
Project description:In this study we performed comprehensive analysis of changes in cell survival, vital parameters, plasticity, as well as transgene expression of placental MSCs after temperature fluctuations within the liquid nitrogen steam storage, mimicking long-term preservation in practical biobanking, transportation, and temporal storage. It was shown that viability and metabolic parameters of placental MSCs did not significantly differ after temperature fluctuations in the range from -196ºC to -100ºC in less than 20 cycles in comparison to constant temperature storage. However, increasing of the temperature range to -80ºC as well as increasing the number of cycles, leads to significant lowering of these parameters after thawing. The number of apoptotic changes increases depending on the number of cycles of temperature fluctuations. Besides, adhesive properties of the cells after thawing are significantly compromised in the samples subjected to temperature fluctuations during storage. Plasticity of placental MSCs was not compromised neither after cryopreservation with constant end temperatures nor with temperature fluctuations. However, regulation of various genes after cryopreservation procedures significantly varies. Alterations in structural and functional parameters of placental MSCs after long-term preservation should be considered in practical biobanking due to potential temperature fluctuations in samples. At the same time, plasticity and transgene expression are not compromised during studied storage conditions, while certain gene regulation is observed.
2017-03-17 | GSE85097 | GEO
Project description:We profiled 116,314 cells using snRNA-seq of 20 frozen lungs obtained from 19 COVID-19 decedents and seven control patients with short postmortem interval (PMI) autopsies. The COVID-19 cohort comprises seven female and 12 male decedents, including 13 patients of Hispanic ethnicity, with an age range from 58 to >89 years who had acquired SARS-CoV-2 infection and succumbed to the disease. The average time from symptom onset to death was 27.5 days (range, 4–63 days). After rapid autopsy with a median PMI of 4 hours (range 2–9 hours) collected tissues were either flash-frozen or frozen following OCT (optimal cutting temperature) embedment and subjected to snRNA-seq using a droplet-based platform (10x Genomics). All included patients had underlying hypertensive disorder and frequently one or more additional co-morbidities associated with increased risk for severe COVID-19.
2021-04-29 | GSE171524 | GEO
Project description:The goal of the Optimal Cutting Temperature (OCT) Embedding Media Study was to measure the effect of OCT embedding on peptide identification. One OCT embedded sample and one snap frozen sample were compared. Each sample was analyzed 3 times using label free proteomic profiling. The data sets below contain the raw data files for the 3 replicates, there were 15 fractions assayed per sample for a total of 45 raw data files. No effect has been identified thus far, so concern over OCT embedding of the TCGA samples has been diminished.<ul><li>Dataset imported into MassIVE from <a href="https://cptac-data-portal.georgetown.edu/cptac/s/S014">https://cptac-data-portal.georgetown.edu/cptac/s/S014</a> on 11/02/18</li></ul>
2018-11-02 | MSV000083095 | MassIVE
Project description:For the RNA-seq experiments, the upper three internodes were excised from 4-week-old plantlets and transferred via micro-cutting to normal nitrogen WPM(NN), which contains 10 mM NO₃⁻ and 5 mM NH₄⁺. After three weeks of rooting, the rooted plantlets were subjected to low-nitrogen (LN) treatment by transferring them to modified WPM containing 0.05 mM NO₃⁻ and 0.025 mM NH₄⁺. Root samples were collected at 0, 6, 12, 24, 48, 96, and 336 hours after LN, each process is repeated three times.
2025-12-03 | GSE306270 | GEO
Project description:Spatial transcriptomics facilitates the understanding of gene expression within complex tissue contexts. Among the array of spatial capture technologies available is 10x Genomics’ Visium which provides whole tissue section profiling, enabling whole transcriptome spatial analysis. Our dataset comprises spleen tissue from mice infected with malaria, spanning multiple experiments and sample preparation protocols for tissue preservation, either as fresh frozen at optimal cutting temperature (OCT) or formalin-fixed paraffin-embedded (FFPE). Tissue placement was also considered, comparing direct tissue placement on the slide with the use of CytAssist (CA), which expands the Visium platform’s capabilities by allowing for the pre-selection of tissue sections and genes through a set of probes. We also include a matching scRNA-seq dataset that can be integrated with the spatial data.
2024-02-26 | GSE254652 | GEO
Project description:RNA sequencing (RNA-seq) coupled with laser capture microdissection (LCM) is a powerful tool for transcriptomic analysis in unfixed fresh-frozen tissues. Fixation of ocular tissues for immunohistochemistry commonly involves the use of paraformaldehyde (PFA) followed by embedding in Optimal Cutting Temperature (OCT) medium for long-term cryopreservation. However, the quality of RNA derived from such archival PFA-fixed/OCT-embedded samples is often compromised, limiting its suitability for transcriptomic studies. In this study, we aimed to develop a methodology to extract high-quality RNA from PFA-fixed canine eyes by utilizing LCM to isolate retinal tissue. We demonstrate the efficacy of an optimized LCM and RNA purification protocol for transcriptomic profiling of PFA-fixed retinal specimens. We compared four pairs of canine retinal tissues, where one eye was subjected to PFA-fixation prior to OCT embedding, while the contralateral eye was embedded fresh frozen (FF) in OCT without fixation. Since the mRNA obtained from PFA-fixed retinas were contaminated with genomic DNA, we employed two rounds of DNase I treatment to obtain RNA suitable for RNA-seq. Notably, the quality of sequencing reads and gene sets identified from both PFA-fixed and FF tissues were nearly identical. In summary, our study introduces an optimized workflow for transcriptomic profiling from PFA-fixed archival retina. This refined methodology paves the way for improved transcriptomic analysis of preserved ocular tissue, bridging the gap between optimal sample preservation and high-quality RNA data acquisition.
2024-05-15 | GSE262625 | GEO
Project description:Tissue samples in biobanks preserved by formalin-fixation and paraffin-embedding (FFPE) and/or optimal cutting temperature (OCT)-embedded and subsequently freezing are highly valuable in experimental studies where the results can be related to clinical parameters. Today, mass spectrometry (MS)-based proteomics is the method of choice for unbiased and relative comparison of the abundances of thousands of proteins present in biological samples. MS analysis of FFPE- and OCT-preserved tissue has been limited, but it is now approachable using newly developed protocols. However, it has not been clarified how the results from different preservation methods agrees and differ. In this study, we use a unique sample set of urinary bladder cancer tissues of two different tumor stages (Ta/T1 – non-muscle invasive and T2/T3 muscle invasive); upon sampling the tumors were divided and preserved by the two methods. Thereafter a protocol for parallel processing of the samples were applied after which the samples were analyzed with label free quantitative MS analysis. Over 700 and 1200 proteins were quantified in FFPE and OCT samples, respectively. Principal component analysis showed that the largest differences between samples are based on the preservation method, but this analysis could also classify the tumors into different stages in each preservation. The overlap of quantifiable proteins between the preservation methods were 84% when all proteins and full data set were taken into consideration, but only 41% on average when proteins from a specific tumor were analyzed. Proteins involved in mitochondrial function were overrepresented among proteins present in OCT data but missing in the FFPE data, indicating that these proteins are not well preserved by FFPE. Moreover, univariate analysis showed that HMGCS2 protein is uniquely quantified in Ta/T1 tumors in both FFPE and OCT data, and that LGALS1, ANXA5 and plastin proteins are upregulated in T2/T3 tumors compared to Ta/T1 tumors in both FFPE and OCT data, confirming the consistency between the data sets and suggesting these proteins as biomarkers. Finally, LGALS1 data were verified by immunohistochemistry staining of an independent data set.
2021-09-09 | PXD020194 | Pride
Project description:Purpose: The goals of this study were to identify expression patterns in human macular neovascularization with spatial transcriptomics Methods: Independent libraries were prepared two human donors: one with macular neovascularation (MNV) and one healthy control. Three tissue sections were taken from the MNV donor and two from the control donor. From the right eyes of both donors, a 4 mm diameter macular punch was collected centered on the fovea centralis, as was a 4 mm peripheral punch approximately 12 mm superotemporal from the macula. Both central and peripheral punches (spanning retina, choroid and sclera) were placed in optimal cutting temperature compound (OCT) and were rapidly snap frozen in liquid nitrogen and stored at -80C. Final libraries were sequenced on an Illumina NovaSeq system. Sequenced reads were mapped to the human genome build hg38 with CellRanger(v7.0.0). Feature selection was performed with the variance stabilizing transformation with Seurat (v4). Results: Spots from the MNV and control donor were deconvoluted with CSIDE, which estimated the percent RNA contribution to each spot from different cell types. Differential expression was performed between the MNV and control donors. Within the area of neovascularization, endothelial cells were predicted to increase expression of genes related to Rho family GTPase signaling and integrin signaling. Likewise, VEGF and TGFB1 were identified as potential upstream regulators that could drive the observed gene expression changes produced by endothelial and retinal pigment epithelium cells in the macular neovascularization donor. Conclusions: Overall, this study spatially analyzes gene expression across the retina, retinal pigment epithelium, and choroid in health and describes a set of candidate molecules that become dysregulated in macular neovascularization.
2023-08-07 | GSE234047 | GEO
Project description:Glioblastoma multiforme (GBM) is the most aggressive malignant primary brain tumor with a dismal mean survival even with the current standard of care. Although in vitro cell systems can provide mechanistic insight into the regulatory networks governing GBM cell proliferation and migration, clinical samples provide a more physiologically relevant view of oncogenic signaling networks. However, clinical samples are not widely available and may be embedded for histopathologic analysis. With the goal of accurately identifying activated signaling networks in GBM tumor samples, we investigated the impact of embedding in optimal cutting temperature (OCT) compound followed by flash freezing in LN2 vs. immediate flash freezing (iFF) in LN2 on protein expression and phosphorylationmediated signaling networks. Quantitative proteomic and phosphoproteomic analysis of 8 pairs of tumor specimens revealed minimal impact of the different sample processing strategies and highlighted the large inter-patient heterogeneity present in these tumors. Correlation analyses of the differentially processed tumor sections identified activated signaling networks present in selected tumors and revealed the differential expression of transcription, translation, and degradation associated proteins. This study demonstrates the capability of quantitative mass spectrometry for identification of in vivo oncogenic signaling networks from human tumor specimens that were either OCT-embedded or immediately flash-frozen.
2014-07-09 | PXD001038 | Pride