scholarly journals Effect of polyethylene glycol 20 000 on protein extraction efficiency of formalin-fixed paraffin-embedded tissues in South Africa

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Sophia Rossouw ◽  
Hocine Bendou ◽  
Liam Bell ◽  
Jonathan Rigby ◽  
Alan Christoffels
Keyword(s):  
Polyethylene Glycol ◽  
Extraction Efficiency ◽  
Protein Extraction ◽  
Formalin Fixed Paraffin ◽  
Liquid Chromatography Tandem Mass ◽  
Formalin Fixed Paraffin Embedded ◽  
Ffpe Tissues ◽  
Protein Selection ◽  
The Impact ◽  
Formalin Fixed

Background: Optimal protocols for efficient and reproducible protein extraction from formalin-fixed paraffin-embedded (FFPE) tissues are not yet standardised and new techniques are continually developed and improved. The effect of polyethylene glycol (PEG) 20 000 on protein extraction efficiency has not been evaluated using human FFPE colorectal cancer tissues and there is no consensus on the protein extraction solution required for efficient, reproducible extraction.Objective: The impact of PEG 20 000 on protein extraction efficiency, reproducibility and protein selection bias was evaluated using FFPE colonic tissue via liquid chromatography tandem mass spectrometry analysis.Methods: This study was conducted from August 2017 to July 2019 using human FFPE colorectal carcinoma tissues from the Anatomical Pathology department at Tygerberg Hospital in South Africa. Samples were analysed via label-free liquid chromatography tandem mass spectrometry to determine the impact of using PEG 20 000 in the protein extraction solution. Data were assessed regarding peptide and protein identifications, method efficiency, reproducibility, protein characteristics and organisation relating to gene ontology categories.Results: Polyethylene glycol 20 000 exclusion increased peptides and proteins identifications and the method was more reproducible compared to the samples processed with PEG 20 000. However, no differences were observed with regard to protein selection bias. We found that higher protein concentrations ( 10 µg) compromised the function of PEG.Conclusion: This study indicates that protocols generating high protein yields from human FFPE tissues would benefit from the exclusion of PEG 20 000 in the protein extraction solution.

scholarly journals Higher PD-L1 Immunohistochemical Detection Signal in Frozen Compared to Matched Paraffin-Embedded Formalin-Fixed Tissues

Antibodies ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 24
Author(s):  
Hazem Ghebeh ◽  
Fatmah A. Mansour ◽  
Dilek Colak ◽  
Akram A. Alfuraydi ◽  
Amal A. Al-Thubiti ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Immunohistochemical Detection ◽  
Breast Cancer Patients ◽  
Preservation Method ◽  
Detection Technology ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Ffpe Tissues ◽  
The Impact ◽  
Formalin Fixed

Purpose: Response to anti-PD-L1/PD-1 immunotherapy correlates with PD-L1 expression in breast cancer. However, the prevalence of PD-L1 positive breast cancer is variable, which could be due to differences in the population/cohort of patients tested or the preservation/detection technology used. To investigate this variability, we examined the effect of two tissue preservation methods on PD-L1 immunohistochemical detection in breast cancer. Methods: We compared PD-L1 expression in patient-matched frozen (FR) and formalin-fixed paraffin-embedded (FFPE) tissues of breast cancer patients. PD-L1 expression was assessed using tumor proportion score (TPS, simply PD-L1 score), and case positivity was determined with PD-L1 score ≥5. Results: In FFPE tissues, PD-L1 was positive in 7–10% of tested patients, depending on the antibody used. In patient-matched FR tissues, the same antibodies showed positive PD-L1 expression in 20–30% of cases. The impact of the antibody tested on the rate of PD-L1 positivity (% of PDL1 positive cases) was minor, as evident in the near perfect concordance between PD-L1 score obtained using the different antibodies whether tested in FR or FFPE tissues. However, there was a systematic drop by an average of 13–20% in the PD-L1 score obtained in FFPE tissues compared to their patient-matched FR tissues. Conclusions: In the tested patient-matched cohort, there was consistently a higher PD-L1 score in FR than FFPE tissues, regardless of the antibody used, demonstrating a significant effect on PD-L1 detection due to the preservation method. These findings should inspire further work to improve the sensitivity of PD-L1 detection and possibly search for more sensitive antibodies in FFPE tissues.

scholarly journals Factors in Tissue Handling and Processing That Impact RNA Obtained From Formalin-fixed, Paraffin-embedded Tissue

2008 ◽  
Vol 56 (11) ◽  
pp. 1033-1042 ◽  
Author(s):  
Joon-Yong Chung ◽  
Till Braunschweig ◽  
Reginald Williams ◽  
Natalie Guerrero ◽  
Karl M. Hoffmann ◽  
...  
Keyword(s):  
Histopathological Examination ◽  
Ffpe Tissue ◽  
Quality Factors ◽  
Rna Quality ◽  
Tissue Processing ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Ffpe Tissues ◽  
The Impact ◽  
Formalin Fixed

Formalin-fixed, paraffin-embedded (FFPE) tissue is the most common specimen available for molecular assays on tissue after diagnostic histopathological examination. RNA from FFPE tissue suffers from strand breakage and cross-linking. Despite excellent extraction methods, RNA quality from FFPE material remains variable. To address the RNA quality factors within FFPE tissues, we studied RNA quality, isolating individual elements of the tissue fixation and processing including length of fixation in formalin and the type of buffer incorporated in the fixative. We examined the impact of the length of the tissue processing cycle as well. The optimal fixation period of 12-24 hr in phosphate-buffered formalin resulted in better-quality RNA. Longer tissue processing times were associated with higher quality RNA. We determined that the middle region of gene suffers less damage by these processes as shown by real-time quantitative RT-PCR. These data provide key information for the development of methods of analysis of gene expression in archival FFPE tissues and contribute to the establishment of objective standards for the processing and handling of tissue in surgical pathology. This manuscript contains online supplemental material at www.jhc.org . Please visit this article online to view these materials.

scholarly journals Characterization of epididymal and testicular histologic lesions and use of immunohistochemistry and PCR on formalin-fixed tissues to detect Brucella canis in male dogs

2021 ◽  
pp. 104063872098688
Author(s):  
Andrea M. Camargo-Castañeda ◽  
Lauren W. Stranahan ◽  
John F. Edwards ◽  
Daniel G. Garcia-Gonzalez ◽  
Leonardo Roa ◽  
...  
Keyword(s):  
Accurate Diagnosis ◽  
Testicular Atrophy ◽  
Detection Techniques ◽  
Formalin Fixed Paraffin ◽  
Brucella Canis ◽  
Formalin Fixed Paraffin Embedded ◽  
Variable Sensitivity ◽  
Ffpe Tissues ◽  
Formalin Fixed

In male dogs, Brucella canis frequently causes epididymitis, ultimately resulting in testicular atrophy and infertility. Although B. canis predominantly affects the epididymis, the misleading term “orchitis” is still commonly used by clinicians. Of additional concern, diagnosis in dogs remains challenging because of variable sensitivity and specificity of serologic assays and fluctuations in bacteremia levels in infected dogs, reducing the sensitivity of blood culture. We describe here the histologic lesions in the scrotal contents of 8 dogs suspected of being infected with B. canis and clinically diagnosed with orchitis. We explored the possibility of using immunohistochemistry (IHC) and real-time PCR (rtPCR) in formalin-fixed, paraffin-embedded (FFPE) tissues to detect the presence of B. canis. Epididymitis of variable chronicity was identified in all 8 dogs, with only 3 also exhibiting orchitis. Using rtPCR, the presence of B. canis was identified in 4 of 8 dogs, with 3 of these 4 dogs also positive by IHC. These results suggest that rtPCR and IHC are promising techniques that can be used in FFPE tissues to detect B. canis when other detection techniques are unavailable. Additionally, accurate recognition of epididymitis rather than orchitis in suspect cases could aid in accurate diagnosis.

scholarly journals The impact of RNA extraction method on accurate RNA sequencing from formalin-fixed paraffin-embedded tissues

BMC Cancer ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Michal Marczyk ◽  
Chunxiao Fu ◽  
Rosanna Lau ◽  
Lili Du ◽  
Alexander J. Trevarton ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Rna Sequencing ◽  
Rna Extraction ◽  
Formalin Fixed Paraffin ◽  
Ffpe Samples ◽  
Formalin Fixed Paraffin Embedded ◽  
The Impact ◽  
Formalin Fixed

Abstract Background Utilization of RNA sequencing methods to measure gene expression from archival formalin-fixed paraffin-embedded (FFPE) tumor samples in translational research and clinical trials requires reliable interpretation of the impact of pre-analytical variables on the data obtained, particularly the methods used to preserve samples and to purify RNA. Methods Matched tissue samples from 12 breast cancers were fresh frozen (FF) and preserved in RNAlater or fixed in formalin and processed as FFPE tissue. Total RNA was extracted and purified from FF samples using the Qiagen RNeasy kit, and in duplicate from FFPE tissue sections using three different kits (Norgen, Qiagen and Roche). All RNA samples underwent whole transcriptome RNA sequencing (wtRNAseq) and targeted RNA sequencing for 31 transcripts included in a signature of sensitivity to endocrine therapy. We assessed the effect of RNA extraction kit on the reliability of gene expression levels using linear mixed-effects model analysis, concordance correlation coefficient (CCC) and differential analysis. All protein-coding genes in the wtRNAseq and three gene expression signatures for breast cancer were assessed for concordance. Results Despite variable quality of the RNA extracted from FFPE samples by different kits, all had similar concordance of overall gene expression from wtRNAseq between matched FF and FFPE samples (median CCC 0.63–0.66) and between technical replicates (median expression difference 0.13–0.22). More than half of genes were differentially expressed between FF and FFPE, but with low fold change (median |LFC| 0.31–0.34). Two out of three breast cancer signatures studied were highly robust in all samples using any kit, whereas the third signature was similarly discordant irrespective of the kit used. The targeted RNAseq assay was concordant between FFPE and FF samples using any of the kits (CCC 0.91–0.96). Conclusions The selection of kit to purify RNA from FFPE did not influence the overall quality of results from wtRNAseq, thus variable reproducibility of gene signatures probably relates to the reliability of individual gene selected and possibly to the algorithm. Targeted RNAseq showed promising performance for clinical deployment of quantitative assays in breast cancer from FFPE samples, although numerical scores were not identical to those from wtRNAseq and would require calibration.

Sarcoma Subgrouping by Detection of Fusion Transcripts Using NanoString nCounter Technology

2018 ◽  
Vol 22 (3) ◽  
pp. 205-213 ◽  
Author(s):  
Javal Sheth ◽  
Anthony Arnoldo ◽  
Yunan Zhong ◽  
Paula Marrano ◽  
Carlos Pereira ◽  
...  
Keyword(s):  
Rt Pcr ◽  
Fusion Transcripts ◽  
Pediatric Sarcoma ◽  
Formalin Fixed Paraffin ◽  
Pediatric Sarcomas ◽  
Formalin Fixed Paraffin Embedded ◽  
Ffpe Tissues ◽  
Nanostring Technology ◽  
Future Work ◽  
Formalin Fixed

Background NanoString technology is an innovative barcode-based system that requires less tissue than traditional techniques and can test for multiple fusion transcripts in a single reaction. The objective of this study was to determine the utility of NanoString technology in the detection of sarcoma-specific fusion transcripts in pediatric sarcomas. Design Probe pairs for the most common pediatric sarcoma fusion transcripts were designed for the assay. The NanoString assay was used to test 22 specific fusion transcripts in 45 sarcoma samples that had exhibited one of these fusion genes previously by reverse transcription polymerase chain reaction (RT-PCR). A mixture of frozen (n = 18), formalin-fixed, paraffin-embedded (FFPE) tissue (n = 23), and rapid extract template (n = 4) were used for testing. Results Each of the 22 transcripts tested was detected in at least one of the 45 tumor samples. The results of the NanoString assay were 100% concordant with the previous RT-PCR results for the tumor samples, and the technique was successful using both FFPE and rapid extract method. Conclusion Multiplexed interrogation for sarcoma-specific fusion transcripts using NanoString technology is a reliable approach for molecular diagnosis of pediatric sarcomas and works well with FFPE tissues. Future work will involve validating additional sarcoma fusion transcripts as well as determining the optimal workflow for diagnostic purposes.

scholarly journals Molecular Markers for Prostate Cancer in Formalin-Fixed Paraffin-Embedded Tissues

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Tamara Sequeiros ◽  
Marta García ◽  
Melania Montes ◽  
Mireia Oliván ◽  
Marina Rigau ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Molecular Markers ◽  
Tumor Grade ◽  
Developed Countries ◽  
Response To Therapy ◽  
Tissue Samples ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Ffpe Tissues ◽  
Formalin Fixed

Prostate cancer (PCa) is the most frequently diagnosed type of cancer in developed countries. The decisive method of diagnosis is based on the results of biopsies, morphologically evaluated to determine the presence or absence of cancer. Although this approach leads to a confident diagnosis in most cases, it can be improved by using the molecular markers present in the tissue. Both miRNAs and proteins are considered excellent candidates for biomarkers in formalin-fixed paraffin-embedded (FFPE) tissues, due to their stability over long periods of time. In the last few years, a concerted effort has been made to develop the necessary tools for their reliable measurement in these types of samples. Furthermore, the use of these kinds of markers may also help in establishing tumor grade and aggressiveness, as well as predicting the possible outcomes in each particular case for the different treatments available. This would aid clinicians in the decision-making process. In this review, we attempt to summarize and discuss the potential use of microRNA and protein profiles in FFPE tissue samples as markers to better predict PCa diagnosis, progression, and response to therapy.

scholarly journals Clostridium perfringens–Associated Necrotic Enteritis-Like Disease in Coconut Lorikeets (Trichoglossus haematodus)

2020 ◽  
pp. 030098582097178
Author(s):  
Llorenç Grau-Roma ◽  
Mauricio Navarro ◽  
Sohvi Blatter ◽  
Christian Wenker ◽  
Sonja Kittl ◽  
...  
Keyword(s):  
Clostridium Perfringens ◽  
Toxin Gene ◽  
Necrotic Enteritis ◽  
Gene Encoding ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Ffpe Tissues ◽  
Polymerase Chain ◽  
Beta Toxin ◽  
Formalin Fixed

Several outbreaks of necrotic enteritis-like disease in lorikeets, from which Clostridium perfringens was consistently isolated, are described. All lorikeets had acute, segmental, or multifocal fibrinonecrotizing inflammatory lesions in the small and/or the large intestine, with intralesional gram-positive rods. The gene encoding C. perfringens alpha toxin was detected by PCR (polymerase chain reaction) on formalin-fixed, paraffin-embedded (FFPE) tissues in 20 out of 24 affected lorikeets (83%), but it was not amplified from samples of any of 10 control lorikeets ( P < .0001). The second most prevalent C. perfringens toxin gene detected was the beta toxin gene, which was found in FFPE from 7 out of 24 affected lorikeets (29%). The other toxin genes were detected inconsistently and in a relatively low number of samples. These cases seem to be associated with C. perfringens, although the specific type involved could not be determined.

scholarly journals Molecular identification of Coccidioides immitis in formalin-fixed, paraffin-embedded (FFPE) tissues from a Colombian patient

2015 ◽  
Vol 53 (5) ◽  
pp. 520-527 ◽  
Author(s):  
Cristina E. Canteros ◽  
Alejandro Vélez H. ◽  
Adriana I. Toranzo ◽  
Roberto Suárez-Alvarez ◽  
Ángela Tobón O. ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Coccidioides Immitis ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Ffpe Tissues ◽  
Formalin Fixed
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