Gli autori desiderano ringraziare il Dott. Cliona M. McHale per criticamente la lettura e la modifica del manoscritto. Questo lavoro è stato finanziato dal National Institute of Environmental Health Sciences, National Institute of Health concessione R01ES017452 a L Zhang.

1. Preparazione del vetrino del campione <ul><li> FISH OctoChrome è stato progettato per esaminare i cambiamenti cromosomici in metafase delle cellule umane, incluso ma non limitato a colture di cellule del sangue periferico, le cellule staminali / progenitrici, e le linee cellulari. I campioni devono essere preparati seguendo la procedura standard per la raccolta di metafasi 3,11-13: impiegando il trattamento Colcemid per arrestare le cellule in metafase, trattamento ipotonico a gonfiare le cellule e fissativo Carnoy di fissare le cellule in sospensione a circa 0,5-1 x 10 6 cellule per ml. </li><li> Pulire il 8-piazza slitta (fornito nel kit OctoChrome, Catalogo #: PMP 803, Cytocell Ltd, Cambridge, Regno Unito, figura 2) mediante immersione in etanolo puro per 2 min. </li><li> Prima di effettuare il diapositiva campione, far cadere una piccola quantità di cellule su un vetrino per controllare la densità delle cellule. Se la densità cella è troppo elevato (celle sovrapposte troppi), diluire la sospensione con fissativo fresco. Se la densità cellulare è troppo bassa (cella troppo pochis su slitta), centrifugare le cellule e risospendere in un volume più piccolo di fissativo fresco. Pipettare pl 5-10 di sospensione cellulare in ciascuna delle 8 aree del vetrino template in una sequenza di quadrati alternati 1/7 - 2/8 - 3/5 - 4/6. Una volta i primi due piazze trovi essiccato all&#39;aria, individuare le piazze rimanenti nello stesso modo. Questo impedirà ai spread cellulari di interferire con l&#39;altro. </li><li> La slitta essiccato può essere conservato a -20 ° C in atmosfera di azoto per maggiore di 5 anni prima ibridazione. </li></ul> 2. Localizzazione di metafasi con un sistema automatizzato <ul><li> Applicare 20 l di 4 &#39;,6-Diamidino-2-fenilindolo (0,2 mg / ml) al centro di ogni metà della slitta e poi coprire con un coprioggetto. </li><li> Eseguire una scansione automatica del vetrino campione di localizzare le cellule in metafase usando Metafer software (MetaSystems, Altlußheim, Germania). Questo facilita la localizzazione di tutte le metafasi e futuri rivalutazione di tutte le immagini delle cellule. </li><li> Guarda i risultati di scansione ed eliminare manualmente non-metafase artefatti. </li></ul> 3. Ibridazione <ol><li> Preparazione del vetrino campione e dispositivo OctoChrome </li><ul><li> Immergere il vetrino campione in tampone 2x SSC a temperatura ambiente per 30 minuti per lavare via DAPI. </li><li> Disidratare il vetrino del campione attraverso una serie di lavaggi con etanolo (2 minuti nel 70%, 85% e 100% etanolo), lasciare asciugare e mettere su un piano di cottura 37 ° C per 5 minuti. </li><li> Posizionare il Multiprobe Camera Chromoprobe Hybridization (fornito nel kit OctoChrome) in un bagno di acqua a 37 ° C e lasciar equilibrare a 37 ° C (+ / - 1 ° C). </li><li> Miscelare la soluzione di ibridazione (fornito nel kit OctoChrome) con ripetute pipettature e pre-riscaldare a 25 microlitri aliquota per dispositivo OctoChrome a 37 ° C. </li><li> Preriscaldare OctoChrome ogni dispositivo (fornito nel kit OctoChrome, vedi figura 2) a 37 ° C posizionando il lato dell&#39;etichetta dispositivo verso il basso su una piastra. NON toccare tche le superfici in rilievo del dispositivo OctoChrome in quanto contengono le sonde. </li></ul><li> Posizionamento del vetrino campione sopra il dispositivo OctoChrome (figura 2) </li><ul><li> Aggiungere 2 pl di pre-riscaldata soluzione di ibridazione a ciascuna delle otto aree sul pre-riscaldato dispositivo OctoChrome mentre rimane a 37 ° C. </li><li> Agitare delicatamente il vetrino sul dispositivo OctoChrome in modo tale che il numero 1, che ora è a testa in giù, si trova sopra la zona alto a destra del dispositivo OctoChrome. Per facilitare la localizzazione di piazza 1, la sua posizione sul dispositivo è stato segnato in Orange. </li><li> Assicurarsi che il vetrino sia ben allineato con le zone corrispondenti sul dispositivo OctoChrome. Abbassare delicatamente il vetrino sopra il dispositivo OctoChrome modo che le gocce di soluzione di ibridazione rendono contatto con la diapositiva. Applica gentile, persino pressione per garantire che la soluzione ibridazione si diffonde ai bordi di ciascuna delle aree in rilievo sul dispositivo OctoChrome. </li><li> Sollevarela slitta / OctoChrome, accuratamente tenendo la fine smerigliato del vetrino, e invertire in modo che la diapositiva è sotto il dispositivo OctoChrome. Assicurarsi che il dispositivo non strisci lungo il vetrino in quanto ciò potrebbe causare la contaminazione incrociata delle sonde. </li><li> Posizionare su un 37 ° C (+ / - 1 ° C) piastra riscaldante per 10 minuti. </li></ul><li> Denaturazione </li><ul><li> Trasferire il dispositivo di scorrimento del campione / OctoChrome alla piastra avendo cura di tenerlo in posizione orizzontale. Assicurarsi che il vetrino campione uniformemente a contatto con la piastra di cottura. </li><li> Denaturare sulla piastra riscaldante a 75 ° C (+ / - 1 ° C) per 5 minuti. </li></ul><li> Ibridazione </li><ul><li> Luogo diapositiva campione / dispositivo OctoChrome alla Camera di ibridazione Chromoprobe Multiprobe. </li><li> Sostituire il coperchio e galleggiare la camera nel 37 ° C (+ / - 1 ° C) bagnomaria (non - agitazione) per una notte. Si prega di notare: NON sigillare il coperchio sulla camera di ibridazione; NON sigillare il coperchio sul bagnomaria; NON ibridarsi in unoincubatore. Questi passaggi sono fondamentali per il controllo dell&#39;umidità. </li></ul><li> Post-ibridazione lavaggi </li><ul><li> Preparazione di soluzioni di lavaggio Soluzione 1: Preparare un Coplin / Hellendahl contenente 0.4x SSC. Equilibrare a 72 ° C (+ / - 1 ° C) in un bagno d&#39;acqua e regolare il pH a 7,0. Soluzione 2: Preparare una Coplin / Hellendahl contenente SSC 2x e Tween 20 0,05%. Lasciare riposare a temperatura ambiente. </li><li> Rimuovere il dispositivo OctoChrome attenzione dal vetrino e porre il vetrino nella soluzione 1 per 2 minuti. </li><li> Immergere il vetrino nella soluzione 2 per 30 secondi. </li></ul></ol> 4. Montaggio e visualizzazione dei risultati <ul><li> Applicare 20 pl di DAPI al centro di ogni metà del il vetrino e applicare un vetrino coprioggetti. </li><li> Incubare al buio per 10 minuti a temperatura ambiente prima vedendo mediante microscopia a fluorescenza. </li></ul> 5. Risultati rappresentativi FiguRe 3A mostra una cellula normale in metafase Square 2. (1) - (3): i cromosomi 8, 21 e 12 sono state dipinte di rosso, verde e blu, e sono visualizzati attraverso una Red Texas, FITC e DEAC filtro, rispettivamente, (4): Visualizzazione attraverso un DAPI / FITC / Texas Red triplo filtro. In generale, i cromosomi dipinti con blu non sono chiare attraverso il filtro tripla e devono essere viste sotto il filtro specifico DEAC. Figura 3B mostra rappresentativi cellule anormali con leucemia specifica traslocazione cromosomica e aneuploidia. (1): t (8; 21), una traslocazione cromosomica comune nella leucemia mieloide acuta, (2): Trisomia 21, tre copie del cromosoma 21, uno aneuploidia comune nella leucemia. <img alt="Figura 1" src="/files/ftp_upload/3619/3619fig1.jpg" /> Figura 1. Disposizione di combinazioni cromosomiche sul dispositivo OctoChrome e risultati attesi pittura cromosomiche. <img alt="Figura 2" src= &quot;/ Files/ftp_upload/3619/3619fig2.jpg&quot; /&gt; Figura 2. Posizionamento del vetrino sul dispositivo OctoChrome. Figura 3. Risultati rappresentativiottenuto da pesce OctoChrome (Piazza 2). <img alt="Figura 3A" src="/files/ftp_upload/3619/3619fig3A.jpg" /> Figura 3A. Una cellula normale con cromosomi 8, 12, 21 dipinti in Piazza 2. <img alt="Figura 3B" src="/files/ftp_upload/3619/3619fig3B.jpg" /> Figura 3B. Rappresentante cellule anomale con leucemia specifica traslocazione cromosomica e aneuploidia in Piazza 2.

<ol>
	<li>Levsky, J. M., Singer, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescence+in+situ+hybridization:+past,+present+and+future.">Fluorescence in situ hybridization: past, present and future.</a> J. Cell. Sci. 116, 2833-2838 (2003).</li><li>Zhang, L., Eastmond, D. A., Smith, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+nature+of+chromosomal+aberrations+detected+in+humans+exposed+to+benzene.">The nature of chromosomal aberrations detected in humans exposed to benzene.</a> Crit. Rev. Toxicol. 32, 1-42 (2002).</li><li>Zhang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aberrations+in+chromosomes+associated+with+lymphoma+and+therapy-related+leukemia+in+benzene-exposed+workers.">Aberrations in chromosomes associated with lymphoma and therapy-related leukemia in benzene-exposed workers.</a> Environ. Mol. Mutagen. 48, 467-474 (2007).</li><li>Zhang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Benzene+increases+aneuploidy+in+the+lymphocytes+of+exposed+workers:+a+comparison+of+data+obtained+by+fluorescence+in+situ+hybridization+in+interphase+and+metaphase.">Benzene increases aneuploidy in the lymphocytes of exposed workers: a comparison of data obtained by fluorescence in situ hybridization in interphase and metaphase.</a> Environ. Mol. Mutagen. 34, 260-268 (1999).</li><li>Zhang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+aneusomy+and+long+arm+deletion+of+chromosomes+5+and+7+in+the+lymphocytes+of+Chinese+workers+exposed+to+benzene.">Increased aneusomy and long arm deletion of chromosomes 5 and 7 in the lymphocytes of Chinese workers exposed to benzene.</a> Carcinogenesis. 19, 1955-1961 (1998).</li><li>Smith, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+translocations+and+aneusomy+in+chromosomes+8+and+21+among+workers+exposed+to+benzene.">Increased translocations and aneusomy in chromosomes 8 and 21 among workers exposed to benzene.</a> Cancer. Res. 58, 2176-2181 (1998).</li><li>Bayani, J., Squire, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+the+detection+of+chromosomal+aberrations+using+spectral+karyotyping.">Advances in the detection of chromosomal aberrations using spectral karyotyping.</a> Clin. Genet. 59, 65-73 (2001).</li><li>Zhang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chromosome-wide+aneuploidy+study+(CWAS)+in+workers+exposed+to+an+established+leukemogen,+benzene.">Chromosome-wide aneuploidy study (CWAS) in workers exposed to an established leukemogen, benzene.</a> Carcinogenesis. 32, 605-612 (2011).</li><li>Rowley, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+chromosome+translocations+in+leukemogenesis.">The role of chromosome translocations in leukemogenesis.</a> Semin. Hematol. 36, 59-72 (1999).</li><li>Zhang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+OctoChrome+fluorescence+in+situ+hybridization+to+detect+specific+aneuploidy+among+all+24+chromosomes+in+benzene-exposed+workers.">Use of OctoChrome fluorescence in situ hybridization to detect specific aneuploidy among all 24 chromosomes in benzene-exposed workers.</a> Chem. Biol. Interact. , 153-154 (2005).</li><li>Barch, M. J., Lawce, H. J., Arsham, M. S., Barch, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> In The ACT cytogenetics laboratory. , 17-30 (1991).</li><li>Zhang, L., Yang, W., Hubbard, A. E., Smith, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nonrandom+aneuploidy+of+chromosomes+1,+5,+6,+7,+8,+9,+11,+12,+and+21+induced+by+the+benzene+metabolites+hydroquinone+and+benzenetriol.">Nonrandom aneuploidy of chromosomes 1, 5, 6, 7, 8, 9, 11, 12, and 21 induced by the benzene metabolites hydroquinone and benzenetriol.</a> Environ. Mol. Mutagen. 45, 388-396 (2005).</li><li>Smith, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydroquinone,+a+benzene+metabolite,+increases+the+level+of+aneusomy+of+chromosomes+7+and+8+in+human+CD34-positive+blood+progenitor+cells.">Hydroquinone, a benzene metabolite, increases the level of aneusomy of chromosomes 7 and 8 in human CD34-positive blood progenitor cells.</a> Carcinogenesis. 21, 1485-1490 (2000).</li><li>Smith, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+understanding+benzene+health+effects+and+susceptibility.">Advances in understanding benzene health effects and susceptibility.</a> Annu. Rev. Public. Health. 31, 133-148 (2010).</li></ol>

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Questo romanzo OctoChrome-FISH test permette di esaminare contemporaneamente tutti i 24 cromosomi umani in una ibridazione solo su una diapositiva. La disposizione delle combinazioni cromosomiche sugli 8 quadrati è stato progettato per facilitare l&#39;identificazione delle non-casuali riarrangiamenti cromosomici nei più comuni leucemie e linfomi. Così, il saggio può rilevare numerico (aneuploidia) nonché strutturali (traslocazioni) alterazioni cromosomiche contemporaneamente. La fase più critica in questo saggio è controllando l&#39;umidità durante l&#39;ibridazione pernottamento in camera di galleggiamento nel bagnomaria. Le sonde FISH e buffer di ibridazione facilmente asciugare se l&#39;umidità è bassa, o diventare eccessivamente diluito, assorbendo troppa umidità, se l&#39;umidità è alta. In entrambi i casi i risultati potrebbe inficiare i risultati. Una modifica possibile superare questa sfida è quella di sigillare il dispositivo OctoChrome e vetrino con nastro adesivo e ibridare su un 37 °; Piastra C durante la notte nel buio. Diapositive campione che sono stati di età compresa troppo può essere inadatto per uso in questo saggio direttamente. Mentre digerendo tali campioni con pepsina migliorerà ibridazione, memorizzare diapositive campione preparati in atmosfera di azoto a -20 ° C è fortemente raccomandato per minimizzare invecchiamento. OctoChrome-FISH è una tecnica promettente per la diagnosi clinica di leucemia e linfoma. E &#39;anche molto utile per esaminare riarrangiamenti cromosomici più specifici relativi alla leucemia e linfoma umano nelle popolazioni esposte a potenziali e leukemogens lymphomagens e per lo studio delle aneuploidie che inducono effetti delle sostanze chimiche in un cromosoma a livello modo. Il nostro studio precedente CWA usando questa tecnica hanno dimostrato che alcuni cromosomi possono essere più colpita rispetto ad altri 8,10 l&#39;esposizione al benzene, una sostanza chimica industriale di primaria importanza e di un inquinante ambientale ubiquitario che provoca la leucemia umana 14.Questo fenomeno di &quot;aneuploidia selettivo&quot; poteva essere esplorato in altre esposizioni chimiche che utilizzano CWA.

<table border="1"><tbody><tr><td> Nome del reattivo </td><td> Azienda </td><td> Numero di catalogo </td><td> Commenti (opzionale) </td><tr><tr><td> OctoChrome Kit </td><td> Cytocell Ltd, Cambridge, UK </td><td> PMP 803 </td><td></td></tr><tr><td> fitoemoagglutinina (PHA) </td><td> Invitrogen Corporation </td><td> 10576-015 </td><td></td></tr><tr><td> Colcemid </td><td> Invitrogen Corporation </td><td> 15212-012 </td><td></td></tr><tr><td> Fissativo di Carnoy </td><td></td><td></td><td> Metanolo: acido acetico glaciale = 3: 1 </td></tr><tr><td> Fluorescenza mimicroscopio </td><td></td><td></td><td> Dotato di filtri per visualizzare DAPI, Texas Red, FITC, e gli spettri cumarina individualmente e uno DAPI / FITC / Texas Red triplo filtro per visualizzare colori diversi contemporaneamente </td></tr><tr><td> Metafer software </td><td> MetaSystems, Altlußheim, Germania </td><td></td><td> Facilitare per individuare tutte le metafasi e di rivalutare le anomalie </td></tr></tbody></table>

chromosomics: detection of numerical and structural alterations in all 24 human chromosomes simultaneously using a novel octochrome fish assay

Ibridazione fluorescente in situ (FISH) è una tecnica che permette sequenze di DNA specifiche per essere rilevato su cromosomi in metafase o interfase in nuclei cella 1. La tecnica utilizza sonde di DNA con sequenze uniche che ibridano a interi cromosomi o specifiche regioni cromosomiche, e serve come un potente strumento in aggiunta alle classiche citogenetica. Per esempio, molti studi precedenti riportato la rilevazione frequente di aberrazioni cromosomiche aumento dei pazienti affetti da leucemia connessi con l&#39;esposizione benzene, benzene-avvelenamento pazienti e lavoratori sani esposti a benzene, utilizzando l&#39;analisi citogenetica classica 2. A base di pesce, alterazioni cromosomiche leucemia-specifici sono stati osservati per essere elevati nei lavoratori apparentemente sani esposti a benzene 3-6, indicando i ruoli critici dei cambiamenti cytogentic a benzene-indotta leucemogenesi. In generale, un test singolo pesce prende in esame solo uno o pochi cromosomi pochi intereo loci specifici per vetrino, in modo ibridazioni più bisogno di essere condotta su più diapositive per coprire tutti i cromosomi umani. Cariotipo spettrale (SKY) permette di visualizzare contemporaneamente l&#39;intero genoma, ma l&#39;esigenza di un apposito software e attrezzature limiti la sua applicazione 7. Qui, descriviamo un nuovo metodo di analisi FISH, OctoChrome-FISH, che può essere applicato per Chromosomics, che definiamo qui come l&#39;analisi simultanea di tutti i 24 cromosomi umani in una diapositiva in studi sull&#39;uomo, come ad esempio il cromosoma studio a livello aneuploidia (CWA) 8. La base del metodo, commercializzato dalla Cytocell come il Sistema Multiprobe Chromoprobe, è un dispositivo OctoChrome che è divisa in 8 quadrati, ciascuno dei quali svolge tre diverse intere sonde pittura cromosomiche (Figura 1). Ciascuno dei tre sonde è marcato direttamente con un fluoroforo colore diverso, verde (FITC), rosso (Texas Red), e blu (cumarina). La disposizione di combinazioni cromosomiche sul OctoChromdispositivo e è stato progettato per facilitare l&#39;identificazione delle non-casuali alterazioni cromosomiche strutturali (traslocazioni) che si trovano nei più comuni leucemie e linfomi, per esempio t (9; 22), t (15; 17), t (8; 21 ), t (14; 18) 9. Inoltre, le variazioni numeriche (aneuploidia) nei cromosomi possono essere rilevati simultaneamente. La diapositiva corrispondente modello è anche diviso in 8 quadrati sulla quale sono vincolati in metafase (Figura 2), e sia posizionata sopra il dispositivo OctoChrome. Le sonde e DNA bersaglio sono denaturato ad alta temperatura e ibridato in una camera umida, e quindi tutte le 24 cromosomi umani possono essere visualizzati simultaneamente. OctoChrome FISH è una tecnica promettente per la diagnosi clinica di leucemia e linfoma e per il rilevamento di aneuploidie in tutti i cromosomi. Abbiamo applicato questo nuovo approccio cromosomica in uno studio CWA dei lavoratori cinesi benzene esposti 8,10.

Watch this Scientific Journal Video about Chromosomics: Detection of Numerical and Structural Alterations in All 24 Human Chromosomes Simultaneously Using a Novel OctoChrome FISH Assay at JoVE.com

Chromosomics: Detection of Numerical and Structural Alterations in All 24 Human Chromosomes Simultaneously Using a Novel OctoChrome FISH Assay

Un romanzo fluorescenza<em&gt; In situ</emIbridazione&gt; (FISH), metodo che prende in esame contemporaneamente sia alterazioni cromosomiche numeriche e strutturali, in particolare le specifiche traslocazioni cromosomiche associate a leucemia e linfoma, di tutti i 24 cromosomi umani su un singolo dispositivo in una ibridazione, è descritto.

Chromosomics: Rilevamento delle alterazioni numeriche e strutturali in tutti i 24 cromosomi umani simultaneamente utilizzando un nuovo metodo di analisi FISH OctoChrome

Fluorescence in situ hybridization (FISH) is a technique that allows specific DNA sequences to be detected on metaphase or interphase chromosomes in cell ...

chromosomics-detection-numerical-structural-alterations-all-24-human

Nanyang Technological University

Research

JoVE Journal

Biology

18.8K Views.  University of California, Berkeley. Un romanzo fluorescenza In situ (FISH), metodo che prende in esame contemporaneamente sia alterazioni cromosomiche numeriche e strutturali, in particolare le specifiche traslocazioni cromosomiche associate a leucemia e linfoma, di tutti i 24 cromosomi umani su un singolo dispositivo in una ibridazione, è descritto.

Video: Chromosomics: Detection of Numerical and Structural Alterations in All 24 Human Chromosomes Simultaneously Using a Novel OctoChrome FISH Assay

Fluorescence in situ hybridization (FISH) Protocol in Human Sperm

Aneuploidies are the most frequent chromosomal abnormalities in humans. Most of these abnormalities result from meiotic errors during the gametogenic process in the parents. In human males, these errors can lead to the production of spermatozoa with numerical chromosome abnormalities which represent an increased risk of transmitting these anomalies to the offspring.
For this reason, the technique of fluorescence in situ hybridization (FISH) on sperm nuclei has become a protocol widely incorporated in the context of clinical diagnosis. This practice provides an estimate of the frequencies of numerical chromosome abnormalities in the gametes of the patients that seek for genetic reproductive advice.
To date, the chromosomes most frequently included in sperm FISH analysis are chromosomes X, Y, 13, 18 and 21.
This video-article describes, step by step, how to process and fix a human semen sample, how to decondense and denature the sperm chromatin, how to proceed to obtain sperm FISH preparations, and how to visualize the results at the microscope. Special remarks of the most relevant steps are given to achieve the best results.

Fluorescence in situ hybridization FISH Protocol in Human Sperm

This video-article describes, step by step, how to process a semen sample to achieve good-quality fluorescence in situ hybridization on human spermatozoa. Preparations obtained can be used for aneuploidy screening in the context of clinical diagnosis.

Fluorescenza In situ</emIbridazione> (FISH) Protocollo di sperma umano

Aneuploidies are the most frequent chromosomal abnormalities in humans. Most of these abnormalities result from meiotic errors during the gametogenic ...

Ricerca

Biologia

High-throughput Saccharification Assay for Lignocellulosic Materials

Polysaccharides that make up plant lignocellulosic biomass can be broken down to produce a range of sugars that subsequently can be 
used in establishing a biorefinery. These raw materials would constitute a new industrial platform, which is both sustainable and carbon neutral, to replace 
the current dependency on fossil fuel. The recalcitrance to deconstruction observed in lignocellulosic materials is produced by several intrinsic properties 
of plant cell walls. Crystalline cellulose is embedded in matrix polysaccharides such as xylans and arabinoxylans, and the whole structure is encased by the 
phenolic polymer lignin, that is also difficult to digest 1. In order to improve the digestibility of plant materials we need to discover the main bottlenecks 
for the saccharification of cell walls and also screen mutant and breeding populations to evaluate the variability in saccharification 2. These tasks require 
a high throughput approach and here we present an analytical platform that can perform saccharification analysis in a 96-well plate format. This platform has 
been developed to allow the screening of lignocellulose digestibility of large populations from varied plant species. We have scaled down the reaction volumes 
for gentle pretreatment, partial enzymatic hydrolysis and sugar determination, to allow large numbers to be assessed rapidly in an automated system.
This automated platform works with milligram amounts of biomass, performing ball milling under controlled conditions to reduce the plant 
materials to a standardised particle size in a reproducible manner. Once the samples are ground, the automated formatting robot dispenses specified and recorded 
amounts of material into the corresponding wells of 96 deep well plate (Figure 1). Normally, we dispense the same material into 4 wells to have 4 replicates for 
analysis. Once the plates are filled with the plant material in the desired layout, they are manually moved to a liquid handling station (Figure 2). In this 
station the samples are subjected to a mild pretreatment with either dilute acid or alkaline and incubated at temperatures of up to 90&deg;C. The pretreatment solution 
is subsequently removed and the samples are rinsed with buffer to return them to a suitable pH for hydrolysis. The samples are then incubated with an enzyme
mixture for a variable length of time at 50&deg;C. An aliquot is taken from the hydrolyzate and the reducing sugars are automatically determined by the MBTH 
colorimetric method.

A simple, rapid method for determining the saccharification potential of large numbers of plant biomass samples is described. The automated platform for this analysis involves the preparation of the plant biomass for analysis in 96 well plates and the subsequent performance of pretreatment, hydrolysis and quantification of the sugars released.

High-throughput per l&#39;analisi Saccarificazione materiali lignocellulosici

Polysaccharides that make up plant lignocellulosic biomass can be broken down to produce a range of sugars that subsequently can be 
used in establishing ...

Detection of Viral RNA by Fluorescence in situ Hybridization (FISH)

Viruses that infect cells elicit specific changes to normal cell functions which serve to divert energy and resources for viral replication. Many aspects of host cell function are commandeered by viruses, usually by the expression of viral gene products that recruit host cell proteins and machineries. Moreover, viruses engineer specific membrane organelles or tag on to mobile vesicles and motor proteins to target regions of the cell (during de novo infection, viruses co-opt molecular motor proteins to target the nucleus; later, during virus assembly, they will hijack cellular machineries that will help in the assembly of viruses). Less is understood on how viruses, in particular those with RNA genomes, coordinate the intracellular trafficking of both protein and RNA components and how they achieve assembly of infectious particles at specific loci in the cell. The study of RNA localization began in earlier work. Developing lower eukaryotic embryos and neuronal cells provided important biological information, and also underscored the importance of RNA localization in the programming of gene expression cascades. The study in other organisms and cell systems has yielded similar important information. Viruses are obligate parasites and must utilise their host cells to replicate. Thus, it is critical to understand how RNA viruses direct their RNA genomes from the nucleus, through the nuclear pore, through the cytoplasm and on to one of its final destinations, into progeny virus particles 1.
FISH serves as a useful tool to identify changes in steady-state localization of viral RNA. When combined with immunofluorescence (IF) analysis 22, FISH/IF co-analyses will provide information on the co-localization of proteins with the viral RNA3. This analysis therefore provides a good starting point to test for RNA-protein interactions by other biochemical or biophysical tests 4,5, since co-localization by itself is not enough evidence to be certain of an interaction. In studying viral RNA localization using a method like this, abundant information has been gained on both viral and cellular RNA trafficking events 6. For instance, HIV-1 produces RNA in the nucleus of infected cells but the RNA is only translated in the cytoplasm. When one key viral protein is missing (Rev) 7, FISH of the viral RNA has revealed that the block to viral replication is due to the retention of the HIV-1 genomic RNA in the nucleus 8. 
Here, we present the method for visual analysis of viral genomic RNA in situ. The method makes use of a labelled RNA probe. This probe is designed to be complementary to the viral genomic RNA. During the in vitro synthesis of the antisense RNA probe, the ribonucleotide that is modified with digoxigenin (DIG) is included in an in vitro transcription reaction. Once the probe has hybridized to the target mRNA in cells, subsequent antibody labelling steps (Figure 1) will reveal the localization of the mRNA as well as proteins of interest when performing FISH/IF.

Detection of Viral RNA by Fluorescence in situ Hybridization FISH

A fluorescence in situ hybridization (FISH) method was developed to visually detect viral genomic RNA using fluorescence microscopy. A probe is made with specificity to the viral RNA that can then be identified using a combination of hybridization and immunofluorescence techniques. This technique offers the advantage of identifying the localization of the viral RNA or DNA at steady-state, providing information on the control of intracellular virus trafficking events.

Rilevamento di RNA virale per fluorescenza<em&gt; In situ</em&gt; Hybridization (FISH)

Viruses  that infect cells elicit specific changes to normal cell functions which serve  to divert energy and resources for viral replication. Many ...

High-throughput Physical Mapping of Chromosomes using Automated in situ Hybridization

Projects to obtain whole-genome sequences for 10,000 vertebrate species1 and for 5,000 insect and related arthropod species2 are expected to take place over the next 5 years. For example, the sequencing of the genomes for 15 malaria mosquitospecies is currently being done using an Illumina platform3,4. This Anopheles species cluster includes both vectors and non-vectors of malaria. When the genome assemblies become available, researchers will have the unique opportunity to perform comparative analysis for inferring evolutionary changes relevant to vector ability. However, it has proven difficult to use next-generation sequencing reads to generate high-quality de novo genome assemblies5. Moreover, the existing genome assemblies for Anopheles gambiae, although obtained using the Sanger method, are gapped or fragmented4,6.
Success of comparative genomic analyses will be limited if researchers deal with numerous sequencing contigs, rather than with chromosome-based genome assemblies. Fragmented, unmapped sequences create problems for genomic analyses because: (i) unidentified gaps cause incorrect or incomplete annotation of genomic sequences; (ii) unmapped sequences lead to confusion between paralogous genes and genes from different haplotypes; and (iii) the lack of chromosome assignment and orientation of the sequencing contigs does not allow for reconstructing rearrangement phylogeny and studying chromosome evolution. Developing high-resolution physical maps for species with newly sequenced genomes is a timely and cost-effective investment that will facilitate genome annotation, evolutionary analysis, and re-sequencing of individual genomes from natural populations7,8.
Here, we present innovative approaches to chromosome preparation, fluorescent in situ hybridization (FISH), and imaging that facilitate rapid development of physical maps. Using An. gambiae as an example, we demonstrate that the development of physical chromosome maps can potentially improve genome assemblies and, thus, the quality of genomic analyses. First, we use a high-pressure method to prepare polytene chromosome spreads. This method, originally developed for Drosophila9, allows the user to visualize more details on chromosomes than the regular squashing technique10. Second, a fully automated, front-end system for FISH is used for high-throughput physical genome mapping. The automated slide staining system runs multiple assays simultaneously and dramatically reduces hands-on time11. Third, an automatic fluorescent imaging system, which includes a motorized slide stage, automatically scans and photographs labeled chromosomes after FISH12. This system is especially useful for identifying and visualizing multiple chromosomal plates on the same slide. In addition, the scanning process captures a more uniform FISH result. Overall, the automated high-throughput physical mapping protocol is more efficient than a standard manual protocol.

High-throughput Physical Mapping of Chromosomes using Automated in situ Hybridization

Genome assemblies based on massively parallel DNA sequencing technologies are usually highly fragmented. The development of physical chromosome maps can potentially improve genome assemblies. Here, we demonstrate innovative approaches to chromosome preparation, fluorescent in situ hybridization, and imaging that significantly increase throughput of the physical map development.

High-throughput mappatura fisica dei cromosomi con modalità automatizzate<em&gt; In situ</em&gt; Ibridazione

Projects to obtain whole-genome sequences for 10,000 vertebrate species1 and for 5,000 insect and related arthropod species2 are expected to take place ...

Detecting Somatic Genetic Alterations in Tumor Specimens by Exon Capture and Massively Parallel Sequencing

Efforts to detect and investigate key oncogenic mutations have proven valuable to facilitate the appropriate treatment for cancer patients. The establishment of high-throughput, massively parallel "next-generation" sequencing has aided the discovery of many such mutations. To enhance the clinical and translational utility of this technology, platforms must be high-throughput, cost-effective, and compatible with formalin-fixed paraffin embedded (FFPE) tissue samples that may yield small amounts of degraded or damaged DNA. Here, we describe the preparation of barcoded and multiplexed DNA libraries followed by hybridization-based capture of targeted exons for the detection of cancer-associated mutations in fresh frozen and FFPE tumors by massively parallel sequencing. This method enables the identification of sequence mutations, copy number alterations, and select structural rearrangements involving all targeted genes. Targeted exon sequencing offers the benefits of high throughput, low cost, and deep sequence coverage, thus conferring high sensitivity for detecting low frequency mutations.

We describe the preparation of barcoded DNA libraries and subsequent hybridization-based exon capture for detection of key cancer-associated mutations in clinical tumor specimens by massively parallel "next generation" sequencing. Targeted exon sequencing offers the benefits of high throughput, low cost, and deep sequence coverage, thus yielding high sensitivity for detecting low frequency mutations.

Rilevamento somatici genetiche Alterazioni in campioni tumorali da Exon Capture e Sequencing Massively Parallel

Efforts  to detect and investigate key oncogenic mutations have proven valuable to  facilitate the appropriate treatment for cancer patients. The ...

Efficient Production and Purification of Recombinant Murine Kindlin-3 from Insect Cells for Biophysical Studies

Kindlins are essential coactivators, with talin, of the cell surface receptors&#160;integrins and also participate in integrin outside-in signalling, and the control of gene transcription in the cell nucleus. The kindlins are ~75 kDa multidomain proteins and bind to an NPxY motif and upstream T/S cluster of the integrin &#946;-subunit cytoplasmic tail. The hematopoietically-important kindlin isoform, kindlin-3, is critical for platelet aggregation during thrombus formation, leukocyte rolling in response to infection and inflammation and osteoclast podocyte formation in bone resorption. Kindlin-3&#39;s role in these processes has resulted in extensive cellular and physiological studies. However, there is a need for an efficient method of acquiring high quality milligram quantities of the protein for further studies. We have developed a protocol, here described, for the efficient expression and purification of recombinant murine kindlin-3 by use of a baculovirus-driven expression system in Sf9 cells yielding sufficient amounts of high purity full-length protein to allow its biophysical characterization. The same approach could be taken in the study of the other mammalian kindlin isoforms.

Kindlins are fundamental to cell adhesion through integrins but studies of them have been hampered by the difficulty encountered in expressing them recombinantly in bacterial hosts. We describe here methods for their efficient production in baculovirus-infected insect cells.

Produzione efficiente e purificazione di ricombinante murino kindlina-3 da cellule di insetto per Biofisica Studies

Kindlins are essential coactivators, with talin, of the cell surface receptors&#160;integrins and also participate in integrin outside-in signalling, and ...

Assessing Species-specific Contributions To Craniofacial Development Using Quail-duck Chimeras

The generation of chimeric embryos is a widespread and powerful approach to study cell fates, tissue interactions, and species-specific contributions to the histological and morphological development of vertebrate embryos. In particular, the use of chimeric embryos has established the importance of neural crest in directing the species-specific morphology of the craniofacial complex. The method described herein utilizes two avian species, duck and quail, with remarkably different craniofacial morphology. This method greatly facilitates the investigation of molecular and cellular regulation of species-specific pattern in the craniofacial complex.&#160;Experiments in quail and duck chimeric embryos have already revealed neural crest-mediated tissue interactions and cell-autonomous behaviors that regulate species-specific pattern in the craniofacial skeleton, musculature, and integument. The great diversity of neural crest derivatives suggests significant potential for future applications of the quail-duck chimeric system to understanding vertebrate development, disease, and evolution.

This article describes a method to generate chimeric embryos that are&#160;designed to test the species-specific contributions of neural crest and/or other tissues to craniofacial development.

Valutare Contributi specie-specifiche per lo sviluppo craniofacciale Uso Chimere Quaglia-anatra

The generation of chimeric embryos is a widespread and powerful approach to study cell fates, tissue interactions, and species-specific contributions to ...

Recombinant Protein Expression for Structural Biology in HEK 293F Suspension Cells: A Novel and Accessible Approach

The expression and purification of large amounts of recombinant protein complexes is an essential requirement for structural biology studies. For over two decades, prokaryotic expression systems such as E. coli have dominated the scientific literature over costly and less efficient eukaryotic cell lines. Despite the clear advantage in terms of yields and costs of expressing recombinant proteins in bacteria, the absence of specific co-factors, chaperones and post-translational modifications may cause loss of function, mis-folding and can disrupt protein-protein interactions of certain eukaryotic multi-subunit complexes, surface receptors and secreted proteins. The use of mammalian cell expression systems can address these drawbacks since they provide a eukaryotic expression environment. However, low protein yields and high costs of such methods have until recently limited their use for structural biology. Here we describe a simple and accessible method for expressing and purifying milligram quantities of protein by performing transient transfections of suspension grown HEK (Human Embryonic Kidney) 293F cells.

The expression of recombinant proteins by mammalian systems is becoming an attractive method for producing protein complexes for structural biology. Here we present a simple yet highly efficient expression system using suspension grown mammalian cells to purify protein complexes for structural studies.

Espressione della proteina ricombinante di Biologia Strutturale in HEK 293F cellule in sospensione: un approccio nuovo e accessibile

The expression and purification of large amounts of recombinant protein complexes is an essential requirement for structural biology studies. For over two ...

Detection of Intracellular Gene Expression in Live Cells of Murine, Human and Porcine Origin Using Fluorescence-labeled Nanoparticles

The reprogramming of somatic cells to induced pluripotent stem cells (iPS) has successfully been performed in different mammalian species including mouse, rat, human, pig and others. The verification of iPS clones mainly relies on the detection of the endogenous expression of different pluripotency genes. These genes mostly represent transcription factors which are located in the cell nucleus. Traditionally, the proof of their endogenous expression is supplied by immunohistochemical staining after fixation of the cells. This approach requires replicate cultures of each clone at this early stage to preserve validated clones for further experiments. The present protocol describes an approach with gene-specific nanoparticles which allows the evaluation of intracellular gene expression directly in live cells by fluorescence. The nanoparticles consist of a central gold particle coupled to a capture strand carrying a sequence complementary to the target mRNA as well as a quenched reporter strand. These nanoparticles are actively endocytosed and the target mRNA displaces the reporter strand which then start to fluoresce. Therefore, specific target gene expression can be detected directly under the microscope. In addition, the emitted fluorescence allows the identification, isolation and enrichment of cells expressing a specific gene by flow cytometry. This method can be applied directly to live cells in culture without any manipulation of the target cells.

This manuscript describes a novel technique which allows the detection of intracellular gene expression after endocytosis of fluorescence-labeled nanoparticles directly in live cells. The method does not require manipulation of the cells and is not restricted with respect to the target gene or species.

Rilevazione di intracellulare genica in cellule vive di murini, umana e suina origine utilizzando nanoparticelle di fluorescenza marcata

The reprogramming of somatic cells to induced pluripotent stem cells (iPS) has successfully been performed in different mammalian species including mouse, ...

Targeted RNA Sequencing Assay to Characterize Gene Expression and Genomic Alterations

RNA sequencing (RNAseq) is a versatile method that can be utilized to detect and characterize gene expression, mutations, gene fusions, and noncoding RNAs. Standard RNAseq requires 30 - 100 million sequencing reads and can include multiple RNA products such as mRNA and noncoding RNAs. We demonstrate how targeted RNAseq (capture) permits a focused study on selected RNA products using a desktop sequencer. RNAseq capture can characterize unannotated, low, or transiently expressed transcripts that may otherwise be missed using traditional RNAseq methods. Here we describe the extraction of RNA from cell lines, ribosomal RNA depletion, cDNA synthesis, preparation of barcoded libraries, hybridization and capture of targeted transcripts and multiplex sequencing on a desktop sequencer. We also outline the computational analysis pipeline, which includes quality control assessment, alignment, fusion detection, gene expression quantification and identification of single nucleotide variants. This assay allows for targeted transcript sequencing to characterize gene expression, gene fusions, and mutations.

We describe a targeted RNA sequencing-based method that includes preparation of indexed cDNA libraries, hybridization and capture with custom probes and data analysis to interrogate selected transcripts for gene expression, mutations, and gene fusions. Targeted RNAseq permits cost-effective, rapid evaluation of selected transcripts on a desktop sequencer.

Mirati RNA Sequencing test per caratterizzare espressione genica e genomica Alterazioni

RNA sequencing (RNAseq) is a versatile method that can be utilized to detect and characterize gene expression, mutations, gene fusions, and noncoding ...