The authors thank the department of Pathology of Hopital Europ&#233;en Georges Pompidou and Necker (Laurianne Chambolle, Elodie Michel, and Gis&#232;le Legall); the Histology platform of PARCC, Hopital Europ&#233;en Georges Pompidou (Corinne Lesaffre); Virginia Clark for language editing; Alexandra Elbakyan for her contribution.

The protocol follows ethical guidelines and was approved by the Ethical Committee (Comit&#233;-de-Protection-des-Personnes Ile-de-France-II, #2015-09-04).
1. Preparation of the materials
<ol>
	<li>Preparation of 1x wash buffer
	<ol>
		<li>Prepare 3 L of 1x wash buffer by adding 2.94 L of distilled water and one bottle (60 mL) of wash buffer (50x) (see the Table of Materials) to a large carboy. Mix well. 
		NOTE: The 1x wash buffer may be prepared ahead ...

<ol>
	<li>Lowy, D. R., Schiller, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reducing+HPV-associated+cancer+globally.">Reducing HPV-associated cancer globally.</a> Cancer Prevention Research.(Philadelphia, PA). 5 (1), 18-23 (2012).</li><li>Laban, S., Hoffmann, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+Papillomavirus+Immunity+in+Oropharyngeal+Cancer:+Time+to+Change+the+Game?.">Human Papillomavirus Immunity in Oropharyngeal Cancer: Time to Change the Game?.</a> Clinical Cancer Research. 24 (3), 505-507 (2018).</li><li>Wiest, T., Schwarz, E., Enders, C., Flechtenmacher, C., Bosch, F. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Involvement+of+intact+HPV16+E6/E7+gene+expression+in+head+and+neck+cancers+with+unaltered+p53+status+and+perturbed+pRb+cell+cycle+control.">Involvement of intact HPV16 E6/E7 gene expression in head and neck cancers with unaltered p53 status and perturbed pRb cell cycle control.</a> Oncogene. 21 (10), 1510-1517 (2002).</li><li>Ndiaye, C., 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=HPV+DNA,+E6/E7+mRNA,+and+p16INK4a+detection+in+head+and+neck+cancers:+a+systematic+review+and+meta-analysis.">HPV DNA, E6/E7 mRNA, and p16INK4a detection in head and neck cancers: a systematic review and meta-analysis.</a> The Lancet Oncology. 15 (12), 1319-1331 (2014).</li><li>Mills, A. M., Dirks, D. C., Poulter, M. D., Mills, S. E., Stoler, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HR-HPV+E6/E7+mRNA+In+Situ+Hybridization.">HR-HPV E6/E7 mRNA In Situ Hybridization.</a> The American Journal of Surgical Pathology. 41 (5), 607-615 (2017).</li><li>Mendez-Pena, J. E., Sadow, P. M., Nose, V., Hoang, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNA+chromogenic+in+situ+hybridization+assay+with+clinical+automated+platform+is+a+sensitive+method+in+detecting+high-risk+human+papillomavirus+in+squamous+cell+carcinoma.">RNA chromogenic in situ hybridization assay with clinical automated platform is a sensitive method in detecting high-risk human papillomavirus in squamous cell carcinoma.</a> Human Pathology. 63, 184-189 (2017).</li><li>Mirghani, H., 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=Diagnosis+of+HPV+driven+oropharyngeal+cancers:+Comparing+p16+based+algorithms+with+the+RNAscope+HPV-test.">Diagnosis of HPV driven oropharyngeal cancers: Comparing p16 based algorithms with the RNAscope HPV-test.</a> Oral Oncology. 62, 101-108 (2016).</li><li>Lewis, J. S., 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=Human+Papillomavirus+Testing+in+Head+and+Neck+Carcinomas:+Guideline+From+the+College+of+American+Pathologists.">Human Papillomavirus Testing in Head and Neck Carcinomas: Guideline From the College of American Pathologists.</a> Archives of Pathology &amp; Laboratory Medicine. 142 (5), 559-597 (2018).</li><li>Mills, A. M., Coppock, J. D., Willis, B. C., Stoler, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HPV+E6/E7+mRNA+In+Situ+Hybridization+in+the+Diagnosis+of+Cervical+Low-grade+Squamous+Intraepithelial+Lesions+(LSIL).">HPV E6/E7 mRNA In Situ Hybridization in the Diagnosis of Cervical Low-grade Squamous Intraepithelial Lesions (LSIL).</a> The American Journal of Surgical Pathology. 42 (2), 192-200 (2018).</li><li>El-Naggar, A., Chan, J. K. C., Grandis, J. R., Takata, T., Slootweg, P. 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> WHO Classification of Head and Neck Tumours. , (2017).</li><li>Ang, K. 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=Human+papillomavirus+and+survival+of+patients+with+oropharyngeal+cancer.">Human papillomavirus and survival of patients with oropharyngeal cancer.</a> The New England Journal of Medicine. 363 (1), 24-35 (2010).</li><li>Badoual, C., 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=PD-1-expressing+tumor-infiltrating+T+cells+are+a+favorable+prognostic+biomarker+in+HPV-associated+head+and+neck+cancer.">PD-1-expressing tumor-infiltrating T cells are a favorable prognostic biomarker in HPV-associated head and neck cancer.</a> Cancer Research. 73 (1), 128-138 (2013).</li><li>Outh-Gauer, S., 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=Immunotherapy+in+head+and+neck+cancers:+a+new+challenge+for+immunologists,+pathologists+and+clinicians.">Immunotherapy in head and neck cancers: a new challenge for immunologists, pathologists and clinicians.</a> Cancer Treatment Reviews. 65, 54-64 (2018).</li><li>Mirghani, H., 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=Diagnosis+of+HPV-driven+head+and+neck+cancer+with+a+single+test+in+routine+clinical+practice.">Diagnosis of HPV-driven head and neck cancer with a single test in routine clinical practice.</a> Modern Pathology. 28 (12), 1518-1527 (2015).</li><li>Bishop, J. 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=Detection+of+Transcriptionally+Active+High-risk+HPV+in+Patients+With+Head+and+Neck+Squamous+Cell+Carcinoma+as+Visualized+by+a+Novel+E6/E7+mRNA+In+Situ+Hybridization+Method.">Detection of Transcriptionally Active High-risk HPV in Patients With Head and Neck Squamous Cell Carcinoma as Visualized by a Novel E6/E7 mRNA In Situ Hybridization Method.</a> The American Journal of Surgical Pathology. 36 (12), 1874-1882 (2012).</li><li>Hsieh, M. -. S., Lee, Y. -. H., Jin, Y. -. T., Huang, W. -. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strong+SOX10+expression+in+human+papillomavirus-related+multiphenotypic+sinonasal+carcinoma:+report+of+6+new+cases+validated+by+high-risk+human+papillomavirus+mRNA+in+situ+hybridization+test.">Strong SOX10 expression in human papillomavirus-related multiphenotypic sinonasal carcinoma: report of 6 new cases validated by high-risk human papillomavirus mRNA in situ hybridization test.</a> Human Pathology. 82, 264-272 (2018).</li><li>Shi, W., 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+Prognostic+Value+of+HPV16+E6+mRNA+Compared+With+In+Situ+Hybridization+for+Human+Oropharyngeal+Squamous+Carcinoma.">Comparative Prognostic Value of HPV16 E6 mRNA Compared With In Situ Hybridization for Human Oropharyngeal Squamous Carcinoma.</a> Journal of Clinical Oncology. 27 (36), 6213-6221 (2009).</li><li>Kuo, K. -. T., 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=The+biomarkers+of+human+papillomavirus+infection+in+tonsillar+squamous+cell+carcinoma&#8212;molecular+basis+and+predicting+favorable+outcome.">The biomarkers of human papillomavirus infection in tonsillar squamous cell carcinoma&#8212;molecular basis and predicting favorable outcome.</a> Modern Pathology. 21 (4), 376-386 (2008).</li><li>Augustin, 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=Evaluation+of+the+efficacy+of+the+four+tests+(p16+immunochemistry,+PCR,+DNA+and+RNA+In+situ+Hybridization)+to+evaluate+a+Human+Papillomavirus+infection+in+head+and+neck+cancers:+a+cohort+of+348+French+squamous+cell+carcinomas.">Evaluation of the efficacy of the four tests (p16 immunochemistry, PCR, DNA and RNA In situ Hybridization) to evaluate a Human Papillomavirus infection in head and neck cancers: a cohort of 348 French squamous cell carcinomas.</a> Human Pathology. , (2018).</li><li>Jung, A. C., 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=Biological+and+clinical+relevance+of+transcriptionally+active+human+papillomavirus+(HPV)+infection+in+oropharynx+squamous+cell+carcinoma.">Biological and clinical relevance of transcriptionally active human papillomavirus (HPV) infection in oropharynx squamous cell carcinoma.</a> International Journal of Cancer. 126 (8), 1882-1894 (2009).</li><li>Augustin, 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=HPV+RNA+CISH+score+identifies+two+prognostic+groups+in+a+p16+positive+oropharyngeal+squamous+cell+carcinoma+population.">HPV RNA CISH score identifies two prognostic groups in a p16 positive oropharyngeal squamous cell carcinoma population.</a> Modern Pathology. , (2018).</li><li>Evans, M. 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=HPV+E6/E7+RNA+In+Situ+Hybridization+Signal+Patterns+as+Biomarkers+of+Three-Tier+Cervical+Intraepithelial+Neoplasia+Grade.">HPV E6/E7 RNA In Situ Hybridization Signal Patterns as Biomarkers of Three-Tier Cervical Intraepithelial Neoplasia Grade.</a> PLOS ONE. 9 (3), e91142 (2014).</li><li>Dreyer, J. H., Hauck, F., Oliveira-Silva, M., Barros, M. H. M., Niedobitek, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+HPV+infection+in+head+and+neck+squamous+cell+carcinoma:+a+practical+proposal.">Detection of HPV infection in head and neck squamous cell carcinoma: a practical proposal.</a> Virchows Archiv. 462 (4), 381-389 (2013).</li><li>Bingham, V., 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=RNAscope+in+situ+hybridization+confirms+mRNA+integrity+in+formalin-fixed,+paraffin-embedded+cancer+tissue+samples.">RNAscope in situ hybridization confirms mRNA integrity in formalin-fixed, paraffin-embedded cancer tissue samples.</a> Oncotarget. , (2017).</li></ol>

HPV RNA CISH performed with a purchased kit is a powerful tool for the detection of viral transcripts and it indicates active HPV infection. Performed manually, the steps of the protocol are overall easy to follow, and the purchased kit is convenient. This technique allows the staining of 19 histological samples plus one control slide at once, and the assay lasts around 8 h. It is critical not to let the samples dry out between steps unless otherwise mentioned. The pretreatment condition may need to be adjusted depending...

HPV RNA CISH is a powerful tool for the detection of active HPV infection, which may prove crucial in benign or malignant lesions in various locations such as the oropharynx or the uterine cervix. The detection of an active HPV infection may support the diagnosis of an HPV-induced lesion and, thereby, influence its treatment and prognosis.
HPV is the most frequent sexually transmitted infection, and over 100 viral genotypes have been described1. Schematically, low-risk genotypes such as genotypes 6 and 11 are known to induce genital warts, recurrent respiratory papillomatosis, and other benign lesions, whereas high-risk genotypes such as genotypes 16 and also 18 are responsible for most cervical cancers and anal cancers and play a role in HNSCC oncogenesis in variable proportions as accounted for by regional epidemiological data2.
Several tools are available for the detection of HPV infection. As a high-risk HPV infection leads to the expression of viral oncogenic proteins E6 and E73, the detection of E6 and E7 transcripts is widely viewed as the gold standard for active HPV infection identification4. HPV RNA CISH can be performed on FFPE samples that are quite easily obtained from patients suffering from various HPV-related diseases. Its performance has been evaluated in squamous intraepithelial neoplasia in the cervix, the anus, and the vagina, and in invasive squamous cell carcinoma in the cervix, the anus, and the upper aerodigestive tract5: it achieves a sensitivity of over 98% among HPV DNA polymerase chain reaction (PCR)-positive cases. This is slightly better than p16 immunostaining (93%) and HPV DNA in situ hybridization (DNA ISH: 97%), which are more commonly used. In another cohort of 57 patients with squamous cell carcinoma (SCC) arising from the head and neck region, the genital region, the skin, and the urinary tract, compared to HPV DNA ISH, HPV RNA CISH achieved better sensitivity (100% versus 88%) and specificity (87% versus 74%)6.
P16 immunostaining is an indirect marker reflecting cell cycle disruption that may be caused (but not exclusively) by HPV infection4,7. This cost-effective test possesses good sensitivity and a negative predictive value and is recommended as a surrogate marker of high-risk HPV infection in oropharynx cancer (OPC) by the College of American Pathologists (CAP) and by the Union for International Cancer Control (UICC)8.
Though this paper solely focuses on the detection of HPV in HNSCC, HPV RNA CISH is clinically relevant in various other conditions that involve HPV infection. For instance, this technique may improve the accuracy of the diagnosis of low-grade squamous intraepithelial lesions of the cervix (LSIL, formerly known as cervical intraepithelial neoplasia, grade 1 [CIN1]) for morphologically ambiguous cases9. Regarding oropharyngeal SCC, HPV RNA CISH allows the identification of HPV-related SCC, labeled as distinct from HPV-unrelated oropharyngeal SCC in the recent eighth edition of the TNM Classification of Head and Neck Cancer (of the Union for International Cancer Control [UICC])10. Since HPV-related SCC exhibits a better prognosis with longer survival and enhanced radiotherapy and chemotherapy sensitivity than HPV-unrelated SCC11,12,13, the detection of HPV infection may impact patient management14,15. Besides, HPV RNA CISH can be used for the diagnosis of HPV-related multiphenotypic sinonasal carcinoma with a higher signal than HPV DNA CISH16. Several multivariate analyses suggest that the detection of E6 and E7 transcripts is correlated with a better prognosis in oropharyngeal SCC overall7,15,17,18 and in the subgroup of p16-positive oropharyngeal SCC19,20.
Here we present the protocol for manual HPV RNA CISH performed on FFPE slides with a kit obtained from the manufacturer.&#160;

<table>
	<tbody>
		<tr>
			<td>Hematoxylin solution, Gill No. 1</td>
			<td>Merck</td>
			<td>GHS132</td>
			<td></td>
		</tr>
		<tr>
			<td>HybEZ Oven (110v)</td>
			<td>Advanced Cell Diagnostics Inc.</td>
			<td>321710</td>
			<td></td>
		</tr>
		<tr>
			<td>HybEZ slide rack</td>
			<td>Advanced Cell Diagnostics Inc.</td>
			<td>300104</td>
			<td></td>
		</tr>
		<tr>
			<td>ImmEdge Hydrophobic Barrier Pen</td>
			<td>Advanced Cell Diagnostics Inc.</td>
			<td>310018</td>
			<td></td>
		</tr>
		<tr>
			<td>RNAscope 2.5 HD Detection Reagents-BROWN</td>
			<td>Advanced Cell Diagnostics Inc.</td>
			<td>322310</td>
			<td>This kit includes amplification reagents AMP1, AMP2, AMP3, AMP4, AMP5 and AMP6, and detection reagents DAB-A and DAB-B</td>
		</tr>
		<tr>
			<td>RNAscope 3-Plex Negative Control Probe</td>
			<td>Advanced Cell Diagnostics Inc.</td>
			<td>320871</td>
			<td>DAPB</td>
		</tr>
		<tr>
			<td>RNAscope 3-Plex Positive Control Probe</td>
			<td>Advanced Cell Diagnostics Inc.</td>
			<td>320861</td>
			<td>PPIB</td>
		</tr>
		<tr>
			<td>RNAscope H202 &#38; Protease Plus Reagent</td>
			<td>Advanced Cell Diagnostics Inc.</td>
			<td>322330</td>
			<td>Hydrogen Peroxyde x2 and Protease Plus x 1</td>
		</tr>
		<tr>
			<td>RNAscope Probe- HPV16/18</td>
			<td>Advanced Cell Diagnostics Inc.</td>
			<td>311121</td>
			<td></td>
		</tr>
		<tr>
			<td>RNAscope Target Retrieval Reagents</td>
			<td>Advanced Cell Diagnostics Inc.</td>
			<td>322000</td>
			<td></td>
		</tr>
		<tr>
			<td>RNAscope Wash Buffer Reagents</td>
			<td>Advanced Cell Diagnostics Inc.</td>
			<td>310091</td>
			<td>Wash Buffer 50X x4</td>
		</tr>
	</tbody>
</table>

chromogenic in situ hybridization as a tool for hpv-related head and neck cancer diagnosis

Human papillomavirus (HPV) infection is a major risk factor for a subtype of oropharyngeal squamous cell carcinoma (OPSCC), which tends to be associated with a better outcome than alcohol- and tobacco-related OPSCC. Chromogenic in situ hybridization (CISH) of HPV viral RNA could allow the semiquantitative evaluation of viral transcripts of the oncogenic proteins E6 and E7 and an in situ visualization with a good spatial resolution. This technique allows the diagnosis of an active infection with the visualization of HPV transcription in the tumoral HPV-infected cells. An advantage of this technique is the avoidance of contamination from nonneoplastic HPV-infected cells adjacent to the tumor. Overall, its good diagnosis performances have it considered to be the gold standard for active HPV infection identification. Since E6 and E7 viral protein interaction with cell proteins pRb and p53 is mandatory for cell transformation, HPV RNA CISH is functionally relevant and acutely reflects active oncogenic HPV infection. This technique is clinically relevant as well since &#34;low&#34; or &#34;high&#34; HPV transcription levels helped the identification of two prognosis groups among HPV-related p16-positive head and neck cancer patients. Here we present the protocol for manual HPV RNA CISH performed on formalin-fixed paraffin-embedded (FFPE) slides with a kit obtained from the manufacturer. Instead of chromogenic revelation, RNA in situ hybridization may also be performed with fluorescent revelation (RNA FISH). It may also be combined with conventional immunostaining.

As described here, in head and neck squamous cell cancer, a case may be considered positive in the presence of brown punctiform staining in the cytoplasm or in the nuclei of tumor cells. In most studies, the signal is considered as either &#8220;positive&#8221; or &#8220;not detected&#8221;14. Methods of semiquantification of the signal have been reported but lack standardization between teams. For example, in some studies, the signals were scored as 1+ with 1&#8211;3 dots per tumor cell, 2+ with ...

Watch this Scientific Journal Video about Chromogenic In Situ Hybridization as a Tool for HPV-Related Head and Neck Cancer Diagnosis at JoVE.com

Chromogenic In Situ Hybridization as a Tool for HPV-Related Head and Neck Cancer Diagnosis

Human papillomavirus (HPV) RNA chromogenic in situ hybridization is considered to be one of the gold standards for active human papillomavirus infection detection within tumors. It allows the visualization of HPV E6-E7 mRNA expression with localization and semiquantitative evaluation of its signal.

Human papillomavirus (HPV) infection is a major risk factor for a subtype of oropharyngeal squamous cell carcinoma (OPSCC), which tends to be associated ...

HPV RNA CISH allows the detection of an active human papilloma virus infection. Since the in-situ hybridization targets HPV RNA this technique allows the visualization of an active transcription of the virus. It has precise spatial resolution and good diagnosis performances.The detection of HPV may support the diagnosis of several HPV-related lesions, such as oropharyngeal squamous cell carcinoma or cervical neoplasia. It may also has an influence on the prognosis. After preparing buffers and counter-staining reagents, prepare one x target retrieval reagent in a large beaker by adding 70 milliliters of 10x target retrieval reagent to 630 milliliters of distilled water.Place the beaker on a heating plate with magnetic stirrer and cover it with aluminum foil. Boil its contents at 100 degrees Celsius for 10 to 15 minutes making sure not to boil it for longer than 30 minutes. To block peroxidase activity on slides with tissue sections previously deparaffinized and placed in the slide rack, add four to six drops, just enough to cover the sample, of hydrogen peroxide to each slide, and incubate them for 10 minutes at room temperature.Wash the slides two times for two minutes in distilled water at room temperature. To break RNA tissue bounds in the RNA tissue sections, first remove the aluminum foil from the boiling one x TRR using a claw, and stop stirring. Immerse the slide rack slowly and very carefully.Cover the beaker again with the aluminum foil, and incubate for 15 minutes. Use the claw to immediately transfer the hot slide rack to a distilled water bath and wash it for two minutes. Wash the slides then in fresh 100%ethanol for two minutes, and let them dry at room temperature for two minutes.Next, use a hydrophobic barrier pen to draw a barrier around each sample, and let it dry out for at least five minutes. For protease digestion, place the slides in the humidity controlled tray, and add approximately four drops of Protease Plus per sample. Cover the tray with a lid, and insert it into the hybridization oven for 30 minutes at 40 degrees Celsius.Remove the tray from the oven, and remove the slide rack. Working one slide at a time, quickly remove any excess liquid, and place the slide in the slide rack submerged in a staining dish filled with distilled water. Wash the slides two times for two minutes in distilled water at room temperature with constant agitation.To start hybridization, tap and flick the slides to remove any excess liquid and place them back in the slide rack. Remove pre-warmed HPV probe from the oven, and add approximately four drops to entirely cover each section. Cover the tray with the lid, and insert it into the oven for two hours at 40 degrees Celsius.After completing incubation, remove the tray from the oven and remove the slide rack. One slide at a time, quickly remove any excess liquid, and place the slide in the slide rack submerged in a staining dish filled with one x wash buffer, washing the slides for two minutes at room temperature with constant agitation, and repeat with fresh one x wash buffer. Tap and flick to remove any excess liquid from the slides, and place them in the slide rack again.Add approximately four drops of room temperature AMP1 per section to entirely cover each section. Cover the tray with the lid, and insert it into the oven for 30 minutes at 40 degrees Celsius. After removing the tray from the oven, remove the slide rack.Working one slide at a time, quickly remove any excess liquid, and place the slide in the slide rack submerged in a staining dish filled with one x wash buffer, washing for two minutes at room temperature with constant agitation, and repeat with fresh one x wash buffer. Dispense the same number of drops of each DAB-A and DAB-B solution in an appropriately sized tube to make approximately 120 microliters of DAB substrate per section, and vortex. Take each slide, one at a time, from the slide rack, and tap and flick to remove excess liquid, and place it back in the slide rack.Pipette approximately 120 microliters of DAB mixture onto each tissue section, making sure that the sections are covered. Incubate for 10 minutes at room temperature, and proceed with counterstaining. Place one drop of mounting medium per glass slat, and then place the slats on the slides and let them air-dry.After a few hours, proceed with evaluation using an optical microscope as described in the manuscript. As described here in head and neck squamous cell carcinoma, presence of brown punctiform staining in the cytoplasm or in the nuclei of tumor cells defined a positive case. The results were divided into two scores, RNA CISH high and low score as observed with a 20x objective.RNA CISH score staining is considered low when observed in under 50%of the tumor cells and covers less than 80%of the cell surface. On the other hand, RNA CISH score is high when observed in more than 50%of the stained cancer cells, or with the staining surface exceeding 80%in more than 30%of the tumor cells. One should never let the slides dry out for hybridization.Do not forget to preheat the probe. For each sample, perform positive and negative control in order to assess the quality of the RNA.

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10.1K vistas.  Paris Descartes University. El ARN del VPH CISH permite la detección de una infección activa por el virus del papiloma humano. Dado que la hibridación in situ se dirige al ARN del VPH, esta técnica permite la visualización de una transcripción activa del virus. Tiene una resolución espacial precisa y un buen diagnóstico.La detección del VPH puede apoyar el diagnóstico de varias lesiones relacionadas con el VPH, como el carcinoma de células escamosas orofaríngeas o la neoplasia cervical. También puede...