Name: optimization for sequencing and analysis of degraded ffpe-rna samples
Uploaded: 2020-06-08T15:00:00
Description: Watch this Scientific Journal Video about Optimization for Sequencing and Analysis of Degraded FFPE-RNA Samples at JoVE.com

Vi er takknemlige til Dr. Danielle Carrick (Division of Cancer Control and Population Sciences, National Cancer Institute) for fortsatt hjelp, spesielt for å initiere denne studien, gi oss prøvene, og for nyttige forslag under dataanalyse. Vi takker oppriktig alle medlemmer av CCR Sequencing Facility ved Frederick National Laboratory for Cancer Research for deres hjelp under prøveforberedelse og sekvensering, spesielt Brenda Ho for hjelp i prøve QC, Oksana tysk for bibliotek QC, Tatyana Smirnova for å kjøre sequencers. Vi vil også takke Tsai-wei Shen og Ashley Walton i Sequencing Facility Bioinformatics Group for å ha hjulpet til med dataanalyse og implementering av RNA-seq-rørledninger. Vi takker også CCBR og NCBR for hjelp med RNaseq analyserørledning og beste praksisutvikling.

1. RNA kvantitet og kvalitetsvurdering
<ol><li>Velg FFPE-prøvene i henhold til forhåndsdefinerte kriterier og trekk ut RNA ved hjelp av en passende metode (f.eks. FFPE-nukleisyreavsugssett, Tabell over materialer). MERK: Det finnes flere forskjellige metoder tilgjengelig for FFPE-RNA-ekstraksjon, inkludert de nyere mikrodisseksjonsmetodene som kan fungere med svært lite vev og trekke ut god kvalitet RNA12,,13,,<sup class="xref"...

<ol>
	<li>Carrick, D. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robustness+of+Next+Generation+Sequencing+on+Older+Formalin-Fixed+Paraffin-Embedded+Tissue.">Robustness of Next Generation Sequencing on Older Formalin-Fixed Paraffin-Embedded Tissue.</a> PLoS One. 10 (7), 0127353 (2015).</li><li>Hedegaard, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Next-generation+sequencing+of+RNA+and+DNA+isolated+from+paired+fresh-frozen+and+formalin-fixed+paraffin-embedded+samples+of+human+cancer+and+normal+tissue.">Next-generation sequencing of RNA and DNA isolated from paired fresh-frozen and formalin-fixed paraffin-embedded samples of human cancer and normal tissue.</a> PLoS One. 9 (5), 98187 (2014).</li><li>Zhang, P., Lehmann, B. D., Shyr, Y., Guo, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Utilization+of+Formalin+Fixed-Paraffin-Embedded+Specimens+in+High+Throughput+Genomic+Studies.">The Utilization of Formalin Fixed-Paraffin-Embedded Specimens in High Throughput Genomic Studies.</a> International Journal of Genomics. 2017, 1926304 (2017).</li><li>Srinivasan, M., Sedmak, D., Jewell, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+fixatives+and+tissue+processing+on+the+content+and+integrity+of+nucleic+acids.">Effect of fixatives and tissue processing on the content and integrity of nucleic acids.</a> American Journal of Pathology. 161 (6), 1961-1971 (2002).</li><li>von Ahlfen, S., Missel, A., Bendrat, K., Schlumpberger, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determinants+of+RNA+quality+from+FFPE+samples.">Determinants of RNA quality from FFPE samples.</a> PLoS One. 2 (12), 1261 (2007).</li><li>Esteve-Codina, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Comparison+of+RNA-Seq+Results+from+Paired+Formalin-Fixed+Paraffin-Embedded+and+Fresh-Frozen+Glioblastoma+Tissue+Samples.">A Comparison of RNA-Seq Results from Paired Formalin-Fixed Paraffin-Embedded and Fresh-Frozen Glioblastoma Tissue Samples.</a> PLoS One. 12 (1), 0170632 (2017).</li><li>Vukmirovic, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+and+validation+of+differentially+expressed+transcripts+by+RNA-sequencing+of+formalin-fixed,+paraffin-embedded+(FFPE)+lung+tissue+from+patients+with+Idiopathic+Pulmonary+Fibrosis.">Identification and validation of differentially expressed transcripts by RNA-sequencing of formalin-fixed, paraffin-embedded (FFPE) lung tissue from patients with Idiopathic Pulmonary Fibrosis.</a> BMC Pulmonary Medicine. 17 (1), 15 (2017).</li><li>Adiconis, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+analysis+of+RNA+sequencing+methods+for+degraded+or+low-input+samples.">Comparative analysis of RNA sequencing methods for degraded or low-input samples.</a> Nature Methods. 10 (7), 623-629 (2013).</li><li>Sinicropi, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole+transcriptome+RNA-Seq+analysis+of+breast+cancer+recurrence+risk+using+formalin-fixed+paraffin-embedded+tumor+tissue.">Whole transcriptome RNA-Seq analysis of breast cancer recurrence risk using formalin-fixed paraffin-embedded tumor tissue.</a> PLoS One. 7 (7), 40092 (2012).</li><li>Altekruse, S. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SEER+cancer+registry+biospecimen+research:+yesterday+and+tomorrow.">SEER cancer registry biospecimen research: yesterday and tomorrow.</a> Cancer Epidemiology, Biomarkers &amp; Prevention. 23 (12), 2681-2687 (2014).</li><li>Zhao, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robustness+of+RNA+sequencing+on+older+formalin-fixed+paraffin-embedded+tissue+from+high-grade+ovarian+serous+adenocarcinomas.">Robustness of RNA sequencing on older formalin-fixed paraffin-embedded tissue from high-grade ovarian serous adenocarcinomas.</a> PLoS One. 14 (5), 0216050 (2019).</li><li>Amini, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+optimised+protocol+for+isolation+of+RNA+from+small+sections+of+laser-capture+microdissected+FFPE+tissue+amenable+for+next-generation+sequencing.">An optimised protocol for isolation of RNA from small sections of laser-capture microdissected FFPE tissue amenable for next-generation sequencing.</a> BMC Molecular Biology. 18 (1), 22 (2017).</li><li>Amini, P., Nassiri, S., Ettlin, J., Malbon, A., Markkanen, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Next-generation+RNA+sequencing+of+FFPE+subsections+reveals+highly+conserved+stromal+reprogramming+between+canine+and+human+mammary+carcinoma.">Next-generation RNA sequencing of FFPE subsections reveals highly conserved stromal reprogramming between canine and human mammary carcinoma.</a> Disease Models and Mechanisms. 12 (8), (2019).</li><li>Wimmer, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systematic+evaluation+of+RNA+quality,+microarray+data+reliability+and+pathway+analysis+in+fresh,+fresh+frozen+and+formalin-fixed+paraffin-embedded+tissue+samples.">Systematic evaluation of RNA quality, microarray data reliability and pathway analysis in fresh, fresh frozen and formalin-fixed paraffin-embedded tissue samples.</a> Scientific Reports. 8 (1), 6351 (2018).</li><li>. Babraham Bioinformatics Available from: <a target="_blank" href="https://www.bioinformatics.babraham.ac.uk/projects/fastqc/">https://www.bioinformatics.babraham.ac.uk/projects/fastqc/</a> (2019)</li><li>Martin, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cutadapt+removes+adapter+sequences+from+high-throughput+sequencing+reads.">Cutadapt removes adapter sequences from high-throughput sequencing reads.</a> EMBnet.journal. 17 (1), 10-12 (2011).</li><li>Bolger, A. M., Lohse, M., Usadel, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trimmomatic:+a+flexible+trimmer+for+Illumina+sequence+data.">Trimmomatic: a flexible trimmer for Illumina sequence data.</a> Bioinformatics. 30 (15), 2114-2120 (2014).</li><li>. Babraham Bioinformatics Available from: <a target="_blank" href="https://www.bioinformatics.babraham.ac.uk/projects/fastq_screen/">https://www.bioinformatics.babraham.ac.uk/projects/fastq_screen/</a> (2019)</li><li>Wood, D. E., Salzberg, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kraken:+ultrafast+metagenomic+sequence+classification+using+exact+alignments.">Kraken: ultrafast metagenomic sequence classification using exact alignments.</a> Genome Biology. 15 (3), 46 (2014).</li><li>Dobin, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=STAR:+ultrafast+universal+RNA-seq+aligner.">STAR: ultrafast universal RNA-seq aligner.</a> Bioinformatics. 29 (1), 15-21 (2013).</li><li>Wang, L., Wang, S., Li, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RSeQC:+quality+control+of+RNA-seq+experiments.">RSeQC: quality control of RNA-seq experiments.</a> Bioinformatics. 28 (16), 2184-2185 (2012).</li><li>Ewels, P., Magnusson, M., Lundin, S., Kaller, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MultiQC:+summarize+analysis+results+for+multiple+tools+and+samples+in+a+single+report.">MultiQC: summarize analysis results for multiple tools and samples in a single report.</a> Bioinformatics. 32 (19), 3047-3048 (2016).</li><li>Li, B., Dewey, C. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RSEM:+accurate+transcript+quantification+from+RNA-Seq+data+with+or+without+a+reference+genome.">RSEM: accurate transcript quantification from RNA-Seq data with or without a reference genome.</a> BMC Bioinformatics. 12, 323 (2011).</li><li>Son, K., Yu, S., Shin, W., Han, K., Kang, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Simple+Guideline+to+Assess+the+Characteristics+of+RNA-Seq+Data.">A Simple Guideline to Assess the Characteristics of RNA-Seq Data.</a> BioMed Research International. 2018, 2906292 (2018).</li><li>McCarthy, D. J., Chen, Y., Smyth, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+expression+analysis+of+multifactor+RNA-Seq+experiments+with+respect+to+biological+variation.">Differential expression analysis of multifactor RNA-Seq experiments with respect to biological variation.</a> Nucleic Acids Research. 40 (10), 4288-4297 (2012).</li><li>Robinson, M. D., McCarthy, D. J., Smyth, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=edgeR:+a+Bioconductor+package+for+differential+expression+analysis+of+digital+gene+expression+data.">edgeR: a Bioconductor package for differential expression analysis of digital gene expression data.</a> Bioinformatics. 26 (1), 139-140 (2010).</li><li>Ritchie, M. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=limma+powers+differential+expression+analyses+for+RNA-sequencing+and+microarray+studies.">limma powers differential expression analyses for RNA-sequencing and microarray studies.</a> Nucleic Acids Research. 43 (7), 47 (2015).</li><li>Subramanian, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+set+enrichment+analysis:+a+knowledge-based+approach+for+interpreting+genome-wide+expression+profiles.">Gene set enrichment analysis: a knowledge-based approach for interpreting genome-wide expression profiles.</a> Proceedings of the National Academy of Sciences of the United States of America U S A. 102 (43), 15545-15550 (2005).</li><li>Mootha, V. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PGC-1alpha-responsive+genes+involved+in+oxidative+phosphorylation+are+coordinately+downregulated+in+human+diabetes.">PGC-1alpha-responsive genes involved in oxidative phosphorylation are coordinately downregulated in human diabetes.</a> Nature Genetics. 34 (3), 267-273 (2003).</li><li>Ashburner, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+ontology:+tool+for+the+unification+of+biology.+The+Gene+Ontology+Consortium.">Gene ontology: tool for the unification of biology. The Gene Ontology Consortium.</a> Nature Genetics. 25 (1), 25-29 (2000).</li><li>Huang da, W., Sherman, B. T., Lempicki, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systematic+and+integrative+analysis+of+large+gene+lists+using+DAVID+bioinformatics+resources.">Systematic and integrative analysis of large gene lists using DAVID bioinformatics resources.</a> Nature Protocols. 4 (1), 44-57 (2009).</li><li>Huang da, W., Sherman, B. T., Lempicki, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioinformatics+enrichment+tools:+paths+toward+the+comprehensive+functional+analysis+of+large+gene+lists.">Bioinformatics enrichment tools: paths toward the comprehensive functional analysis of large gene lists.</a> Nucleic Acids Research. 37 (1), 1-13 (2009).</li><li>Evaluating RNA Quality from FFPE Samples. 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Metoden som er beskrevet her skisserer de viktigste trinnene som kreves for å få gode sekvensdata fra FFPE-RNA-prøver. Hovedpoengene å vurdere med denne metoden er: (1) Sørg for at RNA er bevart så godt som mulig etter ekstraksjon ved å minimere prøvehåndtering og frysing og tining sykluser. Separate QC aliquots er svært nyttig. (2) Bruk en QC-beregning som er best for det angitte eksempelsettet. RIN-verdier og DV200 er ofte ikke nyttige for forringede prøver, og DV100 kan være den foret...

Bruk av neste generasjons sekvenseringsmetoder har gjort oss i stand til å hente et vell av informasjon fra ulike typer prøver. Imidlertid forblir gamle og dårlig bevarte prøver ubrukelige for de vanlige metodene for å generere sekvensdata og krever ofte endringer i veletablerte protokoller. FFPE vev representerer en slik prøvetype som har blitt mye brukt for kliniske prøver1,,2,3. Mens FFPE bevaring opprettholder vevmorfologi, viser nukleinsyrene i FFPE-vev vanligvis et bredt spekter av skade og nedbrytning, noe som gjør det vanskelig å hente den genomiske informasjonen som kan føre til viktig innsikt om molekylære mekanismer som ligger til grunn for ulike lidelser.
Genuttrykksdata generert av RNA-sekvensering er ofte medvirkende til å studere sykdoms- og resistensmekanismer og utfyller DNA-mutasjonsanalyse. RNA er imidlertid mer utsatt for nedbrytning, noe som gjør det mer utfordrende å generere nøyaktige genuttrykksdata fra FFPE-vev. Videre, fordi den brede tilgjengeligheten og rimeligheten av sekvensering er relativt nylig, ble eldre prøver ofte ikke lagret under forhold som kreves for å bevare RNA integritet. Noen av problemene for FFPE prøver inkluderer nedbrytning av RNA på grunn av innebygging i parafin, kjemisk modifikasjon av RNA fører til fragmentering eller refractoriness til enzymatiske prosesser som kreves for sekvensering, og tap av poly-A haler, begrense anvendelsen av oligo-dT som en primer for omvendt transkripsjonase4. En annen utfordring er håndtering/lagring av FFPE-prøver under suboptimale forhold, noe som kan føre til ytterligere nedbrytning av labilemolekyler som RNA i vevene5. Dette er spesielt relevant for eldre prøver som kan ha blitt samlet inn i en tid da genuttrykksanalyse ved RNA-sekvensering ikke var forventet for prøvene. Alle disse fører til redusert kvalitet og kvantitet av den ekstraherte RNA tilgjengelig for generering av nyttige sekvensdata. Den lave sannsynligheten for suksess, kombinert med de høye kostnadene ved sekvensering, har frarådet mange forskere fra å prøve å generere og analysere genuttrykksdata fra potensielt nyttige FFPE-prøver. Noen studier de siste årene har vist brukervennlighet av FFPE vev for genuttrykk analyse2,6,7,8,9, om enn for færre og / eller nyere prøver.
Som en mulighetsstudie brukte vi RNA ekstrahert fra FFPE tumorvevsprøver fra tre gjenværende vevsrepositorier fra Surveillance, Epidemiology, and End Results (SEER) kreftregistre for RNA sekvensering og genuttrykkanalyse10. Anskaffet fra kliniske patologi laboratorier, FFPE vev fra høyverdig ovarie serøse adenokarsinomer ble lagret fra 7-32 år under varierende forhold før RNA utvinning. Fordi i de fleste tilfeller disse blokkene hadde blitt lagret på forskjellige steder i årevis uten forventning om noen sensitiv genetisk analyse i fremtiden, ikke mye omsorg hadde blitt tatt for å bevare nukleinsyrer. Dermed viste de fleste prøvene dårlig kvalitet RNA, med en stor andel av prøvene forurenset med bakterier. Likevel var vi i stand til å utføre genkvantifisering, måle ensartethet og kontinuitet i gendekningen, og utføre Pearson-korrelasjonsanalysen blant biologiske replikasjoner for å måle reproduserbarhet. Basert på et sett med nøkkelsignaturgenpanel sammenlignet vi prøvene i vår studie med The Cancer Genome Atlas (TCGA) data og bekreftet at omtrent 60% av prøvene hadde sammenlignbare genuttrykksprofiler11. Basert på korrelasjonen mellom ulike QC-resultater og eksempelmetadata, identifiserte vi viktige QC-beregninger som har god prediktiv verdi for å identifisere prøver som er mer sannsynlig å generere brukbare sekvensdata11.
Her beskriver vi metodikken som brukes for kvalitetsvurdering av FFPE-RNA, generering av sekvenseringsbiblioteker fra utvunnet RNA-prøver og bioinformatikkanalyse av sekvenseringsdataene.

<table>
	<tbody>
		<tr>
			<td>2100 Bioanalyzer</td>
			<td>Agilent</td>
			<td>G2939BA</td>
			<td></td>
		</tr>
		<tr>
			<td>Agilent DNA 7500 Kit</td>
			<td>Agilent</td>
			<td>5067-1506</td>
			<td></td>
		</tr>
		<tr>
			<td>Agilent High Sensitivity DNA Kit</td>
			<td>Agilent</td>
			<td>5067-4626</td>
			<td></td>
		</tr>
		<tr>
			<td>Agilent RNA 6000 Nano Kit</td>
			<td>Agilent</td>
			<td>5067-1511</td>
			<td></td>
		</tr>
		<tr>
			<td>AllPrep DNA/RNA FFPE Kit</td>
			<td>Qiagen</td>
			<td>80234</td>
			<td></td>
		</tr>
		<tr>
			<td>CFX96 Touch System</td>
			<td>Bio-Rad</td>
			<td>1855195</td>
			<td></td>
		</tr>
		<tr>
			<td>Library Quantification kit v2-Illumina</td>
			<td>KapaBiosystems</td>
			<td>KK4824</td>
			<td></td>
		</tr>
		<tr>
			<td>NEBNext Ultra II Directional RNA Library Prep Kit for Illumina</td>
			<td>New England Biolabs</td>
			<td>E7765S</td>
			<td>https://www.neb.com/protocols/2017/02/07/protocol-for-use-with-ffpe-rna-nebnext-rrna-depletion-kit</td>
		</tr>
		<tr>
			<td>NEBNext rRNA Depletion Kit (Human/Mouse/Rat)</td>
			<td>New England Biolabs</td>
			<td>E6310L</td>
			<td></td>
		</tr>
		<tr>
			<td>NextSeq 500 Sequencing System</td>
			<td>Illumina</td>
			<td>SY-415-1001</td>
			<td>NextSeq 500 System guide: https://support.illumina.com/content/dam/illumina-support/documents/documentation/system_documentation/nextseq/nextseq-500-system-guide-15046563-06.pdf</td>
		</tr>
		<tr>
			<td>NextSeq PhiX Control Kit</td>
			<td>Illumina</td>
			<td>FC-110-3002</td>
			<td></td>
		</tr>
		<tr>
			<td>NSQ 500/550 Hi Output KT v2.5 (150 CYS)</td>
			<td>Illumina</td>
			<td>20024907</td>
			<td></td>
		</tr>
		<tr>
			<td>10X Genomics Magnetic Separator</td>
			<td>10X Genomics</td>
			<td>120250</td>
			<td></td>
		</tr>
		<tr>
			<td>Rotator Multimixer</td>
			<td>VWR</td>
			<td>13916-822</td>
			<td></td>
		</tr>
		<tr>
			<td>C1000 Touch Thermal Cycler</td>
			<td>Bio-Rad</td>
			<td>1851197</td>
			<td></td>
		</tr>
		<tr>
			<td>Sequencing reagent kit</td>
			<td>Illumina</td>
			<td>20024907</td>
			<td></td>
		</tr>
		<tr>
			<td>Flow cell package</td>
			<td>Illumina</td>
			<td>20024907</td>
			<td></td>
		</tr>
		<tr>
			<td>Buffer cartridge and the reagent cartridge</td>
			<td>Illumina</td>
			<td>20024907</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium hydroxide solution (0.2N)</td>
			<td>Millipore Sigma</td>
			<td>SX0607D-6</td>
			<td></td>
		</tr>
		<tr>
			<td>TRIS-HCL Buffer 1.0M, pH 7.0</td>
			<td>Fisher Scientific</td>
			<td>50-151-871</td>
			<td></td>
		</tr>
	</tbody>
</table>

optimization for sequencing and analysis of degraded ffpe-rna samples

Genuttrykksanalyse ved RNA-sekvensering (RNA-seq) muliggjør unik innsikt i kliniske prøver som potensielt kan føre til mekanistisk forståelse av grunnlaget for ulike sykdommer, samt resistens- og/eller mottakelighetsmekanismer. FFPE-vev, som representerer den vanligste metoden for å bevare vevmorfologi i kliniske prøver, er imidlertid ikke de beste kildene til genuttrykkprofileringsanalyse. RNA hentet fra slike prøver er ofte degradert, fragmentert, og kjemisk modifisert, noe som fører til suboptimale sekvensering biblioteker. I sin tur genererer disse sekvensdata av dårlig kvalitet som kanskje ikke er pålitelige for genuttrykksanalyse og mutasjonsoppdagelse. For å få mest mulig ut av FFPE-prøver og få best mulig data fra prøver av lav kvalitet, er det viktig å ta visse forholdsregler mens du planlegger eksperimentell design, forbereder sekvenseringsbiblioteker og under dataanalyse. Dette inkluderer bruk av passende beregninger for nøyaktig prøvekvalitetskontroll (QC), identifisere de beste metodene for ulike trinn under sekvenseringsbibliotekgenerering, og forsiktig bibliotek QC. I tillegg er bruk av riktige programvareverktøy og parametere for sekvensdataanalyse avgjørende for å identifisere artefakter i RNA-seq-data, filtrere ut forurensning og lav kvalitet, vurdere ensartethet av gendekning og måle reproduserbarheten til genuttrykksprofiler blant biologiske replikere. Disse trinnene kan sikre høy nøyaktighet og reproduserbarhet for profilering av svært heterogene RNA-prøver. Her beskriver vi de ulike trinnene for prøve QC, bibliotekforberedelse og QC, sekvensering og dataanalyse som kan bidra til å øke mengden nyttige data hentet fra lav kvalitet RNA, slik som det er hentet fra FFPE-RNA vev.

Metodikken som er beskrevet ovenfor, ble brukt på 67 FFPE-prøver som hadde blitt lagret under en rekke forskjellige forhold i 7–32 år (median lagringstid for prøvene var 17,5 år). Datasettet og analyseresultatene som presenteres her, ble tidligere beskrevet og publisert i Zhao et al.11. Ved kontroll av prøvekvaliteten som beskrevet tidligere (dvs. eksempelspor i figur 2),ble DV100 funnet å være mer nyttig enn DV200 fordi det er mer føl...

Watch this Scientific Journal Video about Optimization for Sequencing and Analysis of Degraded FFPE-RNA Samples at JoVE.com

Optimization for Sequencing and Analysis of Degraded FFPE-RNA Samples

Denne metoden beskriver fremgangsmåten for å forbedre kvaliteten og antallet sekvensdata som kan hentes fra formalin-faste parafin-innebygde (FFPE) RNA-prøver. Vi beskriver metodikken for å mer nøyaktig vurdere kvaliteten på FFPE-RNA-prøver, utarbeide sekvenseringsbiblioteker og analysere dataene fra FFPE-RNA-prøver.

Optimalisering for sekvensering og analyse av degraderte FFPE-RNA-prøver

Gene expression analysis by RNA sequencing (RNA-seq) enables unique insights into clinical samples that can potentially lead to mechanistic understanding ...

Vår protokoll kan brukes til å forbedre kvaliteten og mengden av genuttrykksdata generert fra FFPE-avledede RNA-prøver, spesielt i suboptimale kvalitetsprøver. Denne teknikken vurderer RNA-kvaliteten i FFPE-vevsprøver og muliggjør optimalisering av nedstrømsbehandlingen for å forbedre mengden og kvaliteten på prøvesekvenseringsdataene. Denne metoden tillater omfattende karakterisering av en transkripsjon i biologisk og klinisk prøve og kan gi innsikt i funksjonelle elementer av genomet i utvikling og sykdom.FFPE-RNA-nedbrytningen og utvelgelsen av metodene for eksempel qc, bibliotekforberedelse og dataanalyse kan alle være svært vanskelig. Vær omhyggelig når du velger de riktige metodene og passende kontroller. Visuell demonstrasjon gjør det mulig for seerne å observere de små subtile endringene og forholdsreglene som trengs under planleggingen, vurderingen og sekvenseringsprosessen, spesielt for dårlig bevarte FFPE-prøver.For å sjekke kvaliteten på RNA-prøven, kjør prøven på et RNA QC-system i henhold til produsentens instruksjoner og bruk riktig bioanalyseprogramvare for å analysere fordelingen av RNA-fragmentene i prøven og for å beregne andelen fragmenter som er lengre enn 100 og 200 nukleotider. Basert på QC-beregningene kan du identifisere prøvene med færre enn 40 % av fragmentene som er lengre enn 100 nukleotider for å tillate utelukkelse av disse prøvene fra behandling. For sekvensering, tin de riktige sekvensering reagenssettene i henhold til løpeparametrene i et romtemperaturvannbad og plasser reagensbrettet på fire grader Celsius etter tining.Plasser strømningscellepakken ved romtemperatur i 30 minutter. Mens pakken varmes opp, åpner du Programmet Illumina Experiment Manager og velger Opprett eksempelark. Velg sequenceren som skal brukes, og klikk Neste.Angi strekkoden for reagenssettet og de andre aktuelle arbeidsflytparameterne. Last deretter opp et eksempelark som er opprettet i henhold til Illumina-sekvenskriteriene. For å klargjøre eksempelbiblioteket og kontrollbiblioteket PhiX, denaturere og fortynne bibliotekene til de riktige konsentrasjonene og blande eksempel- og PhiX-kontrollbibliotekene for å oppnå et volumforhold på 5 %PhiX-kontroll.Når strømningscellene er klare, fjern innpakningen, rengjør glassoverflaten med en lofri alkoholsletting og tørk glasset med lavt lolaboratorivev. Fjern reagenskassetten fra fire grader Celsius-lagring og inverter sylinderampullen fem ganger for å blande reagensene. Bank patronen forsiktig på benken for å redusere luftbobler og legg denaturerte og fortynnede prøven inn i reagenskassetten i det angitte reservoaret.Legg strømningscellen, bufferkassetten og reagenskassetten på systemet. Utfør deretter en automatisk kontroll og se gjennom utdataene for å sikre at kjøreparametrene passerer systemkontrollen. Når den automatiske kontrollen er fullført, velger du start for å starte sekvenseringskjøringen.Hvis du vil visualisere resultatene for QC før behandling og etter justering, kjører du multi-QC for å generere en aggregert rapport i HTML-format. Hvis du vil fastslå satsvise effekter og vurdere kvalitetstilordningen for det angitte datasettet, bruker du et R-skript til å kjøre en hovedkomponentanalyse. Eksempelkorrelasjonsanalyse kan deretter utføres ved hjelp av Pearson-korrelasjonen mellom ulike prøver.Estimeringen av andelen fragmenter som er lengre enn 100 nukleotider er mer nyttig enn en estimering av fragmentene som er lengre enn 200 nukleotider fordi det er mer følsomt for nøyaktig måling av andelen mindre fragmentstørrelser for svært nedbrutte RNA-prøver. Gitt den høye graden av nedbrytning i prøvesettet, anbefales en total RNA-bibliotekforberedelsesmetode. Her vises for eksempel sekvenseringsbiblioteker utarbeidet fra fire forskjellige eksempler.Her vises oversikter over rå FastQ-filsekvenseringskvalitet og eksempelkortinnhold. FastQC screening kan bidra til å oppdage forurensning som bakteriell eller mus forurensning i prøvene. STAR-justering kan brukes til å bestemme andelen av lesinger som er tilordnet referansegenomet, prosentandelen av leser unikt tilordnet referansegenomet, og andelen lesinger som ikke var tilordnet, eller som ble tilordnet til flere loci.Kortet og RSeQC-statistikken kan brukes til å bestemme prosentandelen av messenger RNA-er, intronic- og intergene baser som finnes i de tilordnede lysene. For disse representative analysene hadde noen degraderte biblioteker en tre hovedbias der flere lesere ble kartlagt nærmere de tre prime enn til de fem prime end. I tillegg kan hovedkomponentanalyse utføres for å bestemme prosentandelen av den totale variasjonen som fanges opp av hovedkomponentene for de biologiske replikeringene i hvert utvalg.Vær forsiktig med å unngå forringelse av prøver, klargjør repliker og flere strøk for hvert utvalg, bruk de riktige beregningene til å vurdere utvalgskvaliteten og bruke riktig bibliotekforberedelsesmetode. Ved hjelp av denne metodikken kan større NGS-studier utføres med tidligere ubrukelige FFPE-prøver med varierende lagringstider og forhold for å få innsikt i en rekke forskjellige sykdomstilstander. Denne teknikken banet vei for forskere å studere eksisterende store arkiver av FFPE utvalg med rik klinisk informasjon og kan i stor grad forbedre populasjonsbaserte kreftstudier.

optimization-for-sequencing-and-analysis-of-degraded-ffpe-rna-samples

Research

JoVE Journal

Genetics

Flow-sorting and Exome Sequencing of the Reed-Sternberg Cells of Classical Hodgkin Lymphoma

The Hodgkin Reed-Sternberg cells of classical Hodgkin lymphoma are sparsely distributed within a background of inflammatory lymphocytes and typically comprise less than 1% of the tumor mass. Material derived from bulk tumor contains tumor content at a concentration insufficient for characterization. Therefore, fluorescence activated cell sorting using eight antibodies, as well as side- and forward-scatter, is described here as a method of rapidly separating and concentrating with high purity thousands of HRS cells from the tumor for subsequent study. At the same time, because standard protocols for exome sequencing typically require 100-1,000 ng of input DNA, which is often too high, even with flow sorting, we also provide an optimized, low-input library construction protocol capable of producing high-quality data from as little as 10 ng of input DNA. This combination is capable of producing next-generation libraries suitable for hybridization capture of whole-exome baits or more focused targeted panels, as desired. Exome sequencing of the HRS cells, when compared against healthy intratumor T or B cells, can identify somatic alterations, including mutations, insertions and deletions, and copy number alterations. These findings elucidate the molecular biology of HRS cells and may reveal avenues for targeted drug treatments.

Here, we describe a combined flow cytometric cell sorting and low-input, next-generation library construction protocol designed to produce high-quality, whole-exome data from the Hodgkin Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (CHL).

Flow-sortering og Exome Sequencing av Reed-Sternberg-cellene av klassisk Hodgkin-lymfom

The Hodgkin Reed-Sternberg cells of classical Hodgkin lymphoma are sparsely distributed within a background of inflammatory lymphocytes and typically ...

Detection of Copy Number Alterations Using Single Cell Sequencing

Detection of genomic changes at single cell resolution is important for characterizing genetic heterogeneity and evolution in normal tissues, cancers, and microbial populations. Traditional methods for assessing genetic heterogeneity have been limited by low resolution, low sensitivity, and/or low specificity. Single cell sequencing has emerged as a powerful tool for detecting genetic heterogeneity with high resolution, high sensitivity and, when appropriately analyzed, high specificity. Here we provide a protocol for the isolation, whole genome amplification, sequencing, and analysis of single cells. Our approach allows for the reliable identification of megabase-scale copy number variants in single cells. However, aspects of this protocol can also be applied to investigate other types of genetic alterations in single cells.

Single cell sequencing is an increasingly popular and accessible tool for addressing genomic changes at high resolution. We provide a protocol that uses single cell sequencing to identify copy number alterations in single cells.

Påvisning av Kopier nummer Endringer Bruke enkelt celle Sequencing

Detection of genomic changes at single cell resolution is important for characterizing genetic heterogeneity and evolution in normal tissues, cancers, and ...

Optimization and Comparative Analysis of Plant Organellar DNA Enrichment Methods Suitable for Next-generation Sequencing

Plant organellar genomes contain large, repetitive elements that may undergo pairing or recombination to form complex structures and/or sub-genomic fragments. Organellar genomes also exist in admixtures within a given cell or tissue type (heteroplasmy), and an abundance of subtypes may change throughout development or when under stress (sub-stoichiometric shifting). Next-generation sequencing (NGS) technologies are required to obtain deeper understanding of organellar genome structure and function. Traditional sequencing studies use several methods to obtain organellar DNA: (1) If a large amount of starting tissue is used, it is homogenized and subjected to differential centrifugation and/or gradient purification. (2) If a smaller amount of tissue is used (i.e., if seeds, material, or space is limited), the same process is performed as in (1), followed by whole-genome amplification to obtain sufficient DNA. (3) Bioinformatics analysis can be used to sequence the total genomic DNA and to parse out organellar reads. All these methods have inherent challenges and tradeoffs. In (1), it may be difficult to obtain such a large amount of starting tissue; in (2), whole-genome amplification could introduce a sequencing bias; and in (3), homology between nuclear and organellar genomes could interfere with assembly and analysis. In plants with large nuclear genomes, it is advantageous to enrich for organellar DNA to reduce sequencing costs and sequence complexity for bioinformatics analyses. Here, we compare a traditional differential centrifugation method with a fourth method, an adapted CpG-methyl pulldown approach, to separate the total genomic DNA into nuclear and organellar fractions. Both methods yield sufficient DNA for NGS, DNA that is highly enriched for organellar sequences, albeit at different ratios in mitochondria and chloroplasts. We present the optimization of these methods for wheat leaf tissue and discuss major advantages and disadvantages of each approach in the context of sample input, protocol ease, and downstream application.

The comparison and optimization of two plant organellar DNA enrichment methods are presented: traditional differential centrifugation and fractionation of the total gDNA based on methylation status. We assess the resulting DNA quantity and quality, demonstrate performance in short-read next-generation sequencing, and discuss the potential for use in long-read single-molecule sequencing.

Optimalisering og sammenligningsanalyse av organellar DNA-berigelsesmetoder som er egnet for neste generasjons sekvensering

Plant organellar genomes contain large, repetitive elements that may undergo pairing or recombination to form complex structures and/or sub-genomic ...

Generation of Native Chromatin Immunoprecipitation Sequencing Libraries for Nucleosome Density Analysis

We present a modified native chromatin immunoprecipitation sequencing (ChIP-seq) experimental protocol compatible with a Gaussian mixture distribution based analysis methodology (nucleosome density ChIP-seq; ndChIP-seq) that enables the generation of combined measurements of micrococcal nuclease (MNase) accessibility with histone modification genome-wide. Nucleosome position and local density, and the posttranslational modification of their histone subunits, act in concert to regulate local transcription states. Combinatorial measurements of nucleosome accessibility with histone modification generated by ndChIP-seq allows for the simultaneous interrogation of these features. The ndChIP-seq methodology is applicable to small numbers of primary cells inaccessible to cross-linking based ChIP-seq protocols. Taken together, ndChIP-seq enables the measurement of histone modification in combination with local nucleosome density to obtain new insights into shared mechanisms that regulate RNA transcription within rare primary cell populations.

We present a modified native chromatin immunoprecipitation sequencing (ChIP-seq) methodology for the generation of sequence datasets suitable for a nucleosome density ChIP-seq analytical framework integrating micrococcal nuclease (MNase) accessibility with histone modification measurements.

Generasjon av innfødte Chromatin Immunoprecipitation sekvensering biblioteker til Nucleosome tetthet analyse

We present a modified native chromatin immunoprecipitation sequencing (ChIP-seq) experimental protocol compatible with a Gaussian mixture distribution ...

Chromatin Immunoprecipitation (ChIP) Protocol for Low-abundance Embryonic Samples

Chromatin immunoprecipitation (ChIP) is a widely-used technique for mapping the localization of post-translationally modified histones, histone variants, transcription factors, or chromatin-modifying enzymes at a given locus or on a genome-wide scale. The combination of ChIP assays with next-generation sequencing (i.e., ChIP-Seq) is a powerful approach to globally uncover gene regulatory networks and to improve the functional annotation of genomes, especially of non-coding regulatory sequences. ChIP protocols normally require large amounts of cellular material, thus precluding the applicability of this method to investigating rare cell types or small tissue biopsies. In order to make the ChIP assay compatible with the amount of biological material that can typically be obtained in vivo during early vertebrate embryogenesis, we describe here a simplified ChIP protocol in which the number of steps required to complete the assay were reduced to minimize sample loss. This ChIP protocol has been successfully used to investigate different histone modifications in various embryonic chicken and adult mouse tissues using low to medium cell numbers (5 x 104 - 5 x 105 cells). Importantly, this protocol is compatible with ChIP-seq technology using standard library preparation methods, thus providing global epigenomic maps in highly relevant embryonic tissues.

Chromatin Immunoprecipitation ChIP Protocol for Low-abundance Embryonic Samples

Here, we describe a chromatin immunoprecipitation (ChIP) and ChIP-seq library preparation protocol to generate global epigenomic profiles from low-abundance chicken embryonic samples.

Chromatin Immunoprecipitation (ChIP) protokollen for lav-overflod embryonale prøver

Chromatin immunoprecipitation (ChIP) is a widely-used technique for mapping the localization of post-translationally modified histones, histone variants, ...

Robust DNA Isolation and High-throughput Sequencing Library Construction for Herbarium Specimens

Herbaria are an invaluable source of plant material that can be used in a variety of biological studies. The use of herbarium specimens is associated with a number of challenges including sample preservation quality, degraded DNA, and destructive sampling of rare specimens. In order to more effectively use herbarium material in large sequencing projects, a dependable and scalable method of DNA isolation and library preparation is needed. This paper demonstrates a robust, beginning-to-end protocol for DNA isolation and high-throughput library construction from herbarium specimens that does not require modification for individual samples. This protocol is tailored for low quality dried plant material and takes advantage of existing methods by optimizing tissue grinding, modifying library size selection, and introducing an optional reamplification step for low yield libraries. Reamplification of low yield DNA libraries can rescue samples derived from irreplaceable and potentially valuable herbarium specimens, negating the need for additional destructive sampling and without introducing discernible sequencing bias for common phylogenetic applications. The protocol has been tested on hundreds of grass species, but is expected to be adaptable for use in other plant lineages after verification. This protocol can be limited by extremely degraded DNA, where fragments do not exist in the desired size range, and by secondary metabolites present in some plant material that inhibit clean DNA isolation. Overall, this protocol introduces a fast and comprehensive method that allows for DNA isolation and library preparation of 24 samples in less than 13 h, with only 8 h of active hands-on time with minimal modifications.

This article demonstrates a detailed protocol for DNA isolation and high-throughput sequencing library construction from herbarium material including rescue of exceptionally poor-quality DNA.

Robust DNA isolasjon og høy gjennomstrømming sekvensering biblioteket konstruksjon for Herbarium prøver

Herbaria are an invaluable source of plant material that can be used in a variety of biological studies. The use of herbarium specimens is associated with ...

Rare Event Detection Using Error-corrected DNA and RNA Sequencing

Conventional next-generation sequencing techniques (NGS) have allowed for immense genomic characterization for over a decade. Specifically, NGS has been used to analyze the spectrum of clonal mutations in malignancy. Though far more efficient than traditional Sanger methods, NGS struggles with identifying rare clonal and subclonal mutations due to its high error rate of ~0.5&#8211;2.0%. Thus, standard NGS has a limit of detection for mutations that are &#62;0.02 variant allele fraction (VAF). While the clinical significance for mutations this rare in patients without known disease remains unclear, patients treated for leukemia have significantly improved outcomes when residual disease is &#60;0.0001 by flow cytometry. In order to mitigate this artefactual background of NGS, numerous methods have been developed. Here we describe a method for Error-corrected DNA and RNA Sequencing (ECS), which involves tagging individual molecules with both a 16 bp random index for error-correction and an 8 bp patient-specific index for multiplexing. Our method can detect and track clonal mutations at variant allele fractions (VAFs) two orders of magnitude lower than the detection limit of NGS and as rare as 0.0001 VAF.

Next-generation sequencing (NGS) is a powerful tool for genomic characterization that is limited by the high error rate of the platform (~0.5&#8211;2.0%). We describe our methods of error-corrected sequencing that allow us to obviate the NGS error rate and detect mutations at variant allele fractions as rare as 0.0001.

Sjelden hendelse gjenkjenning feil-korrigert DNA og RNA sekvensering

Conventional next-generation sequencing techniques (NGS) have allowed for immense genomic characterization for over a decade. Specifically, NGS has been ...

Amplification of Near Full-length HIV-1 Proviruses for Next-Generation Sequencing

The Full-Length Individual Proviral Sequencing (FLIPS) assay is an efficient and high-throughput method designed to amplify and sequence single, near full-length (intact and defective), HIV-1 proviruses. FLIPS allows determination of the genetic composition of integrated HIV-1 within a cell population. Through identifying defects within HIV-1 proviral sequences that arise during reverse transcription, such as large internal deletions, deleterious stop codons/hypermutation, frameshift mutations, and mutations/deletions in cis acting elements required for virion maturation, FLIPS can identify integrated proviruses incapable of replication. The FLIPS assay can be utilized to identify HIV-1 proviruses that lack these defects and are&#160;therefore potentially replication-competent. The FLIPS protocol involves: lysis of HIV-1 infected cells, nested PCR of near full-length HIV-1 proviruses (using primers targeted to the HIV-1 5&#39; and 3&#39; LTR), DNA purification and quantification, library preparation for Next-generation Sequencing (NGS), NGS, de novo assembly of proviral contigs, and a simple process of elimination for identifying replication-competent proviruses. FLIPS provides advantages over traditional methods designed to sequence integrated HIV-1 proviruses, such as single-proviral sequencing. FLIPS amplifies and sequences near full-length proviruses enabling replication competency to be determined, and also uses fewer amplification primers, preventing the consequences of primer mismatches. FLIPS is a useful tool for understanding the genetic landscape of integrated HIV-1 proviruses, especially within the latent reservoir, however, its utilization can extend to any application in which the genetic composition of integrated HIV-1 is required.

Full-length individual proviral sequencing (FLIPS) provides an efficient and high-throughput method for the amplification and sequencing of single, near full-length (intact and defective) HIV-1 proviruses and allows for determination of their potential replication-competency. FLIPS overcomes limitations of previous assays designed to sequence the latent HIV-1 reservoir.

Forsterkning av nær full lengde HIV-1-Proviruses for neste generasjons sekvensering

The Full-Length Individual Proviral Sequencing (FLIPS) assay is an efficient and high-throughput method designed to amplify and sequence single, near ...

Semiconductor Sequencing for Preimplantation Genetic Testing for Aneuploidy

Chromosomal aneuploidy, one of the main causes leading to embryonic development arrest, implantation failure, or pregnancy loss, has been well documented in human embryos. Preimplantation genetic testing for aneuploidy (PGT-A) is a genetic test that significantly improves reproductive outcomes by detecting chromosomal abnormalities of embryos. Next-generation sequencing (NGS) provides a high-throughput and cost-effective approach for genetic analysis and has shown clinical applicability in PGT-A. Here, we present a rapid and low-cost semiconductor sequencing-based NGS method for screening of aneuploidy in embryos. The first step of the workflow is whole genome amplification (WGA) of the biopsied embryo specimen, followed by construction of sequencing library, and subsequent sequencing on the semiconductor sequencing system. Generally, for a PGT-A application, 24 samples can be loaded and sequenced on each chip generating 60&#8722;80 million reads at an average read length of 150 base pairs. The method provides a refined protocol for performing template amplification and enrichment of sequencing library, making the PGT-A detection reproducible, high-throughput, cost-efficient, and timesaving. The running time of this semiconductor sequencer is only 2&#8722;4 hours, shortening the turnaround time from receiving samples to issuing reports into 5 days. All these advantages make this assay an ideal method to detect chromosomal aneuploidies from embryos and thus, facilitate its wide application in PGT-A.

Here, we introduce a semiconductor sequencing method for preimplantation genetic testing for aneuploidy (PGT-A) with the advantages of short turnaround time, low cost, and high throughput.

Semiconductor sekvensering for Preimplantation genetisk testing for avvik

Chromosomal aneuploidy, one of the main causes leading to embryonic development arrest, implantation failure, or pregnancy loss, has been well documented ...

Sequencing of mRNA from Whole Blood using Nanopore Sequencing

Sequencing in remote locations and resource-poor settings presents unique challenges. Nanopore sequencing can be successfully used under such conditions, and was deployed to West Africa during the recent Ebola virus epidemic, highlighting this possibility. In addition to its practical advantages (low cost, ease of equipment transport and use), this technology also provides fundamental advantages over second-generation sequencing approaches, particularly the very long read length, ability to directly sequence RNA, and real-time availability of data. Raw read accuracy is lower than with other sequencing platforms, which represents the main limitation of this technology; however, this can be partially mitigated by the high read depth generated. Here, we present a field-compatible protocol for sequencing of the mRNAs encoding for Niemann-Pick C1, which is the cellular receptor for ebolaviruses. This protocol encompasses extraction of RNA from animal blood samples, followed by RT-PCR for target enrichment, barcoding, library preparation, and the sequencing run itself, and can be easily adapted for use with other DNA or RNA targets.

Nanopore sequencing is a novel technology that allows cost-effective sequencing in remote locations and resource-poor settings. Here, we present a protocol for sequencing of mRNAs from whole blood that is compatible with such conditions.

Sekvensering av mRNA fra hele Blood bruke Nanopore sekvensering

Sequencing in remote locations and resource-poor settings presents unique challenges. Nanopore sequencing can be successfully used under such conditions, ...