Questa ricerca è stata finanziata dal Canada Genomics di Ricerca e Sviluppo Health Initiative (GRDI) e la strategia di regolamentazione canadese per la biotecnologia (CRSB). Gli autori non hanno alcun conflitto di interessi.

<ol>
	<li>Helbock, H. J., Beckman, K. B., Shigenaga, M. K., Walter, P. B., Woodall, A. A., Yeo, H. C., Ames, B. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA+oxidation+matters:+The+HPLC-electrochemical+assay+of+8-oxo-deoxyguianosine+and+8-oxo-guanine.">DNA oxidation matters: The HPLC-electrochemical assay of 8-oxo-deoxyguianosine and 8-oxo-guanine.</a> Proc. Natl. Acad. Sci. 95 (1), 288-293 (1998).</li><li>Valavanidis, A., Vlachogianni, T., Fiotakis, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=8-hydroxy-2'+-deoxyguanosine+(8-OHdG):+A+critical+biomarker+of+oxidative+stress+and+carcinogenesis.">8-hydroxy-2' -deoxyguanosine (8-OHdG): A critical biomarker of oxidative stress and carcinogenesis.</a> J. Environ. Sci Health C Environ. Carcinog. Ecotoxicol. Rev. 27 (2), 120-139 (2009).</li><li>Cadet, J., Bellon, S., Douki, T., Frelon, S., Gasparutto, D., Muller, E., Pouget, J. P., Ravanat, J. L., Romieu, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radiation-induced+DNA+damage:+formation,+measurement,+and+biochemical+features.">Radiation-induced DNA damage: formation, measurement, and biochemical features.</a> J Environ Pathol Toxicol Oncol. 23 (1), 23-23 (2004).</li><li>Weiss, J. M., Goode, E. L., Ladiges, W. C., Ulrich, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymorphic+variation+in+hOGG1+and+risk+of+cancer:+a+review+of+the+functional+and+epidemiologic+literature.">Polymorphic variation in hOGG1 and risk of cancer: a review of the functional and epidemiologic literature.</a> Mol. Carcinog. 42 (3), 127-141 (2005).</li><li>Culp, S. J., Cho, B. P., Kadlubar, F. F., Evans, F. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+and+Conformational+Analyses+of+8-hydroxy-2'-deoxyguanosine.">Structural and Conformational Analyses of 8-hydroxy-2'-deoxyguanosine.</a> Chem. Res. Toxicol. 2 (6), 416-422 (1989).</li><li>Cooke, M. S., Loft, S., Olinski, R., Evans, M. D., Bialkowski, K., Wagner, J. R., Dedon, P. C., M&#248;ller, P., Greenberg, M. M., Cadet, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recommendations+for+standardized+description+of+and+nomenclature+concerning+oxidatively+damaged+nucleobases+in+DNA.">Recommendations for standardized description of and nomenclature concerning oxidatively damaged nucleobases in DNA.</a> Chem. Res. Toxicol. 23 (4), 705-707 (2010).</li><li>Jang, Y. H., Goddard, W. A. 3. r. d., Noyes, K. T., Sowers, L. C., Hwang, S., Chung, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=First+principles+calculations+of+the+tautomers+and+pKa+values+of+8-oxoguanine:+implications+for+mutagenicity+and+repair.">First principles calculations of the tautomers and pKa values of 8-oxoguanine: implications for mutagenicity and repair.</a> Chem. Res. Toxicol. 15 (8), 1023-1035 (2002).</li><li>Park, J. -. H., Gopishetty, S., Szewczuk, L. M., Troxel, A. B., Harvey, R. G., Penning, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+8-oxo-7,8-dihydro-2'-deoxyguanosine+(8-oxo-dGuo)+by+PAH+o-quinones:+involvement+of+reactive+oxygen+species+and+copper(ii)/copper(i)+redox+cycling.">Formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo) by PAH o-quinones: involvement of reactive oxygen species and copper(ii)/copper(i) redox cycling.</a> Chem. Res. Toxicol. 18 (6), 1026-1037 (2005).</li><li>Mangal, D., Vudathala, D., Park, J. H., Lee, S. H., Penning, T. M., Blair, I. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+7,8-dihydro-8-oxo-2'-deoxyguanosine+in+cellular+DNA+during+oxidative+stress.">Analysis of 7,8-dihydro-8-oxo-2'-deoxyguanosine in cellular DNA during oxidative stress.</a> Chem. Res. Toxicol. 22 (5), 788-797 (2009).</li><li>Ravanat, J. L., Douki, T., Duez, P., Gremaud, E., Herbert, K., Hofer, T., Lasserre, L., Saint-Pierre, C., Favier, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+background+level+of+8-oxo-7,8-dihydro-2'-deoxyguanosine:+an+isotope+based+method+to+evaluate+artefactual+oxidation+of+DNA+during+its+extraction+and+subsequent+work-up.">Cellular background level of 8-oxo-7,8-dihydro-2'-deoxyguanosine: an isotope based method to evaluate artefactual oxidation of DNA during its extraction and subsequent work-up.</a> Carcinogenesis. 23 (11), 1911-1918 (2002).</li><li>Gossen, J. A., De Leeuw, W. J. F., Tan, C. H. T., Zwarthoff, E. C., Berends, F., Lohman, P. H. M., Knook, D. L., Vijg, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+rescue+of+integrated+shuttle+vectors+from+transgenic+mice:+A+model+for+studying+mutations+in+vivo.">Efficient rescue of integrated shuttle vectors from transgenic mice: A model for studying mutations in vivo.</a> Proc. Natl. Acad. Sci. U.S.A. 86 (20), 7971-7975 (1989).</li><li>Van Campen, L. E., Murphy, W. J., Franks, J. R., Mathias, P. I., Toraason, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidative+DNA+damage+is+associated+with+intense+noise+exposure+in+the+rat.">Oxidative DNA damage is associated with intense noise exposure in the rat.</a> Hear Res. 164 (1-2), 164-161 (2002).</li><li>European Standards Committee on Oxidative DNA Damage (ESCODD). <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+DNA+oxidation+in+human+cells+by+chromatographic+and+enzymic+methods.">Measurement of DNA oxidation in human cells by chromatographic and enzymic methods.</a> Free Radic. Biol. Med. 34 (8), 1089-1099 (2003).</li><li>Rebelo, I. A., Piedade, J. A., Oliveira-Brett, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+an+HPLC+method+with+electrochemical+detection+of+femtomoles+of+8-oxo-7,8-dihydroguanine+and+8-oxo-7,8-dihydro-2'-deoxyguanosine+in+the+presence+of+uric+acid.">Development of an HPLC method with electrochemical detection of femtomoles of 8-oxo-7,8-dihydroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine in the presence of uric acid.</a> Talanta. 63 (2), 323-331 (2004).</li><li>Ravanat, J. -. L., Turesky, R. J., Gremaud, E., Trudel, L. J., Stadler, 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=Determination+of+8-oxoguanine+in+DNA+by+gas+chromatography-mass+spectrometry+and+HPLC-electrochemical+detection:+overestimation+of+the+background+level+of+the+oxidized+base+by+the+gas+chromatography-mass+spectrometry+assay.">Determination of 8-oxoguanine in DNA by gas chromatography-mass spectrometry and HPLC-electrochemical detection: overestimation of the background level of the oxidized base by the gas chromatography-mass spectrometry assay.</a> Chem. Res. Toxicol. 8 (8), 1039-1045 (1995).</li><li>Kawanishi, S., Murata, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanism+of+DNA+damage+induced+by+bromate+differs+from+general+types+of+oxidative+stress.">Mechanism of DNA damage induced by bromate differs from general types of oxidative stress.</a> Toxicology. 221 (2-3), 172-178 (2006).</li><li>Tahara, S., Kaneko, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Susceptibility+of+mouse+splenic+cells+to+oxidative+DNA+damage+by+x-ray+irradiation.">Susceptibility of mouse splenic cells to oxidative DNA damage by x-ray irradiation.</a> Biol. Pharm. Bull. 27 (1), 105-108 (2004).</li><li>Garratt, L. W., Mistry, V., Singh, R., Sandhu, J. K., Sheil, B., Cooke, M. S., Sly, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interpretation+of+urinary+8-oxo-7,8-dihydro-2'-deoxyguanosine+is+adversely+affected+by+methodological+inaccuracies+when+using+a+commercial+ELISA.">Interpretation of urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine is adversely affected by methodological inaccuracies when using a commercial ELISA.</a> Free Radic. Biol. Med. 48 (11), 1460-1464 (2012).</li><li>Cooke, M. S., Collins, A., Olinski, R., Rozalski, R., Loft, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Harmonising+measurements+of+8-oxo-7,8-dihydro-2&#8242;-deoxyguanosine+in+cellular+DNA+and+urine.">Harmonising measurements of 8-oxo-7,8-dihydro-2&#8242;-deoxyguanosine in cellular DNA and urine.</a> Free Radic. Res. 46 (4), 541-553 (2012).</li><li>Cadet, J., Douki, T., Ravanat, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+oxidatively+generated+base+damage+in+cellular+DNA.">Measurement of oxidatively generated base damage in cellular DNA.</a> Mutat Res. 711 (1-2), 3-12 (2011).</li><li>Chomczynski, P., Mackey, K., Drews, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNAzol:+a+reagent+for+the+rapid+isolation+of+genomic+DNA.">DNAzol: a reagent for the rapid isolation of genomic DNA.</a> Biotechniques. 22 (3), 550-553 (1997).</li><li>Collins, A. R., Cadet, J., M&#246;ller, L., Poulsen, H. E., Vi&#241;a, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Are+we+sure+we+know+how+to+measure+8-oxo-7,8-dihydroguanine+in+DNA+from+human+cells.">Are we sure we know how to measure 8-oxo-7,8-dihydroguanine in DNA from human cells.</a> Arch Biochem Biophys. 423 (1), 57-65 (2004).</li><li>Badouard, C., M&#233;n&#233;zo, Y., Panteix, G., Ravanat, J. L., Douki, T., Cadet, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+new+types+of+DNA+lesions+in+human+sperm.">Determination of new types of DNA lesions in human sperm.</a> Zygote. 16 (1), 9-13 (2008).</li><li>Cadet, J., Douki, T., Gasparutto, D., Ravanat, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidative+damage+to+DNA:+formation,+measurement+and+biochemical+features.">Oxidative damage to DNA: formation, measurement and biochemical features.</a> Mutat Res. 531 (1-2), 1-2 (2003).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Validation of analytical procedures: text and methodology Q2(R1). , (2015).</li></ol>

No conflict of interest or competing financial interests declared.

Anche se a 8-oxo-dGuo &#39;stato segnalato come un utile biomarcatore di ossidazione del DNA, la sua quantificazione affidabile può rappresentare una sfida. Anche se esistono diversi metodi pubblicati, vi è la necessità di un approccio globale, panoramica descrittiva di protocollo per consentire ai ricercatori di implementare il metodo nei loro laboratori. Qui vi presentiamo una panoramica dettagliata di un protocollo basato su HPLC che permetterà ai nuovi utenti di stabilire un metodo efficace per il rilevamento a ...

Specie reattive dell&#39;ossigeno (ROS), i cui livelli di stato stazionario può aumentare durante molte condizioni patologiche e metabolismo xenotoxic, contribuiscono ad una maggiore frequenza di danno ossidativo al DNA. Tra diverse possibili basi azotate prodotti di ossidazione, danno ossidativo del DNA può essere facilmente misurata utilizzando il marcatore stabile 8-oxo-7,8-diidro-2&#39;-deossiguanosina (8-oxo-dGuo), che è una delle forme ossidate di 2 &#39; -deoxyguanosine (dGuo) 1. 8-oxo-dGuo è il più abbondante lesione DNA 2 e, di conseguenza, è stato studiato per maggiore dettaglio come biomarker di ossidazione DNA nonostante l&#39;esistenza di DNA multiple prodotti di ossidazione 3. Negli esseri umani, questo danno può essere riparato con la base di riparazione per escissione dell&#39;8-oxoguanine glicosilasi 1 (hOGG1) 4. Se lasciato non riparata, 8-oxo-dGuo può contribuire alla formazione di base di mutazioni coppia-di sostituzione (cioè, G a T trasversioni) 4. È importante sottolineare che, a 8-oxo-dGuo è un marcatore consolidata for danni al DNA in relazione alla iniziazione e promozione di carcinogenesi 2. Pertanto, la quantificazione precisa di 8-oxo-dGuo è un biomarker utile e desiderabile di danno ossidativo del DNA 5. C&#39;è confusione diffusa nella letteratura per quanto riguarda i nomi corretti per i moduli ossidativamente-danneggiati di 2-deossiguanosina e, inoltre, il nome corretto del composto (s) di routine misurato come biomarker di danno ossidativo del DNA 6. I 6,8-dicheto e 6-enolica, 8-cheto forme tautomere di 8-oxo-dGuo (illustrata nella figura 1) sono i due tautomeri più importanti discussi in letteratura 5,7. La forma 6,8-dicheto è la forma più prominente a pH fisiologico di 7,4, ed è il più importante prodotto di ossidazione DNA 7. Pertanto, 8-oxo-dGuo, piuttosto che a 8-idrossi-dGuo è il nome più appropriato per questo prodotto di ossidazione 6. E &#39;anche importante notare che il 2-deossiguanosina (dGuo), piuttosto che nucleobase guanina (Gua) o guanosina ribonucleosidi (Guo), rispettivamente, viene rilevato dalla maggior parte dei metodi di 6. La rilevazione accurata e la quantificazione di 8-oxo-dGuo è difficile a causa: i) la variabilità nella digestione del campione di DNA, ii) ossidazione accidentale di dGuo a 8-oxo-dGuo che può verificarsi durante la preparazione del campione, e iii) la necessità per la convalida efficace del metodo HPLC-ED analitica 8. In questo protocollo, abbiamo puntato a raggiungere i) offrendo condizioni favorevoli, per la completa digestione del DNA e ii) da parte del chelante inclusione metallo e soluzioni ferrochelanti trattati e un DNA di isolamento speciale reagente, mentre iii) solo parzialmente affrontati dalla inclusione di controlli positivi e fornendo in tal modo che il metodo è in grado di rilevare 8-oxo-dGuo in campioni biologici. Ulteriore convalida va oltre lo scopo di questo articolo. Tuttavia, siamo fiduciosi che questo protocollo aiuterà il futuroutenti di determinare la misura in cui essi devono convalidare formalmente il protocollo, a seconda dei loro fini. Un elenco di passi necessari per la validazione formale del metodo è fornito ulteriormente. Durante lo sviluppo e la diffusione di un metodo di rilevazione a 8-oxo-dGuo, metodi pubblicati sono stati rivisti e consolidati. Così, questo metodo elimina la necessità di raccogliere informazioni da diverse fonti pubblicati che spesso mancano di importanti dettagli sperimentali fornendo allo stesso tempo mezzi rapidi e semplici di test, se è stato adottato il metodo per l&#39;individuazione e la quantificazione di 8-oxo-dGuo con successo. Questo metodo adatto è stato impiegato con successo per analizzare campioni di DNA da cellule in coltura e tessuti murino. Questo articolo video aiuterà altri gruppi a stabilire un metodo efficace per un rilevamento affidabile e quantificazione di 8-oxo-dGuo mediante HPLC-ED.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>8-oxo-dGuo standard</td>
			<td>Cayman Chemical Company</td>
			<td>89320</td>
			<td>Inappropriately referred to as &#34;8-hydroxy-2&#39;-deoxy Guanosine&#34; - see Fig. 1 and text for details</td>
		</tr>
		<tr>
			<td>Alkaline phosphatase&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>P5931</td>
			<td>From E.coli</td>
		</tr>
		<tr>
			<td>Chelex 100</td>
			<td>Sigma-Aldrich</td>
			<td>C7901</td>
			<td>Chelates heavy metals</td>
		</tr>
		<tr>
			<td>Desferoxamine mesylate</td>
			<td>Sigma-Aldrich</td>
			<td>D9533</td>
			<td></td>
		</tr>
		<tr>
			<td>dGuo standard</td>
			<td>Sigma-Aldrich</td>
			<td>D7145</td>
			<td></td>
		</tr>
		<tr>
			<td>Dibasic sodium phosphate</td>
			<td>Sigma-Aldrich</td>
			<td>S9390</td>
			<td></td>
		</tr>
		<tr>
			<td>DNA from salmon sperm</td>
			<td>Sigma-Aldrich</td>
			<td>D1626</td>
			<td>Sodium salt</td>
		</tr>
		<tr>
			<td>DNase I</td>
			<td>Sigma-Aldrich</td>
			<td>D4527</td>
			<td>TypeII, from bovine pancreas</td>
		</tr>
		<tr>
			<td>DNAzol</td>
			<td>Invitrogen</td>
			<td>10503-27</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethylenediaminetetraacetic acid disodium salt dihydrate (EDTA)</td>
			<td>Sigma-Aldrich</td>
			<td>E4884</td>
			<td>The compound would not completely dissolve until solution pH is adjusted to 8.0 with e.g. NaOH</td>
		</tr>
		<tr>
			<td>F12-K media</td>
			<td>ATCC</td>
			<td>30-2004</td>
			<td></td>
		</tr>
		<tr>
			<td>Foetal bovine serum</td>
			<td>ATCC</td>
			<td>30-2020</td>
			<td></td>
		</tr>
		<tr>
			<td>Guard column</td>
			<td>Chromatographic Specialties</td>
			<td>YBA 99S03 0204GC</td>
			<td>Protects colum from contamination; may also lead to pressure build-up</td>
		</tr>
		<tr>
			<td>Magnesium chloride</td>
			<td>Sigma-Aldrich</td>
			<td>M8266</td>
			<td></td>
		</tr>
		<tr>
			<td>Monobasic sodium phosphate</td>
			<td>Sigma-Aldrich</td>
			<td>S9638</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>Invitrogen</td>
			<td>15140-122</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate buffered saline</td>
			<td>Invitrogen</td>
			<td>15190-250</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphodiesterase I enzyme&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>P3243</td>
			<td>Type II from Crotalus adamaneus venom</td>
		</tr>
		<tr>
			<td>Teflon homogenizer</td>
			<td>Thomas Scientific</td>
			<td>7724T-1 or 7724T-5 for 1 or 5 mL, respectively</td>
			<td>Volume (holding capacity) depends on the amount of sample to be processed.</td>
		</tr>
		<tr>
			<td>Trypsin</td>
			<td>Invitrogen</td>
			<td>15050-065</td>
			<td></td>
		</tr>
		<tr>
			<td>YMC-BASIC column with bonded spherical silica</td>
			<td>Chromatographic Specialties</td>
			<td>YBA 99S03 1546WT</td>
			<td></td>
		</tr>
	</tbody>
</table>

hplc measurement of the dna oxidation biomarker, 8-oxo-7,8-dihydro-2&#8217;-deoxyguanosine, in cultured cells and animal tissues

Lo stress ossidativo è associato con molti processi fisiologici e patologici, nonché metabolismo xenobiotico, porta alla ossidazione di Biomacromolecules, compreso il DNA. Pertanto, la rilevazione efficiente di ossidazione del DNA è importante per una varietà di discipline di ricerca, tra cui la medicina e tossicologia. Un biomarcatore comune di DNA ossidativo danneggiato è di 8-oxo-7,8-diidro-2&#39;-deossiguanosina (8-oxo-dGuo; spesso erroneamente indicato come 8-idrossi-2&#39;-deossiguanosina (8-OH-dGuo o 8 -oxo-dG)). Sono stati descritti diversi protocolli per 8-oxo-dGuo misurazione ad alta pressione cromatografia liquida con rivelazione elettrochimica (HPLC-ED). Tuttavia, questi sono stati applicati principalmente DNA purificato trattati con pro-ossidanti. Inoltre, a causa delle differenze metodologiche tra laboratori, principalmente a causa delle differenze di allestimento di analisi, l&#39;adozione di metodi pubblicati per il rilevamento di 8-oxo-dGuo mediante HPLC-DE richiede un&#39;attenta ottimizzazione da ciascun laboratorio. Laprotocollo, descrivendo un tale processo di ottimizzazione, è carente. Qui, un protocollo dettagliato è descritto per la rilevazione di 8-oxo-dGuo mediante HPLC-DE, DNA da cellule o tessuti animali. Esso illustra come preparazione del campione di DNA può essere facilmente e rapidamente ottimizzato per minimizzare indesiderabile ossidazione DNA che può verificarsi durante la loro preparazione. Questo protocollo mostra come rilevare 8-oxo-dGuo in cellule coltivate umane adenocarcinoma alveolare (cioè cellule A549) trattati con l&#39;agente ossidante KBrO 3, e dalla milza di topi esposti al dibenzo idrocarburi aromatici policiclici (DEF, p) crisene (DBC, precedentemente noto come dibenzo (a, l) pirene, Dalp). Nel complesso, questo lavoro illustra come un metodo HPLC-ED può essere facilmente ottimizzato per il rilevamento di 8-oxo-dGuo in campioni biologici.

dGuo stato osservato per avere un tempo di ritenzione di 4,7 min, mentre 8-oxo-dGuo aveva un tempo di ritenzione di circa 6,4 min (Figura 2A e B). Vi è circa 1.000 volte differenza nelle altezze tra i due analiti, come si vede nella Figura 2C. Voltammograms per 8-oxo-dGuo e dGuo stati ottenuti per gli standard che funzionano a potenziale lavorativo nell&#39;intervallo 0,2-1,1 V. Il potenziale di lavoro ottimale per 8-oxo-dGuo è risultata di +0,5 V e +0,9 V per dGuo <s...

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HPLC Measurement of the DNA Oxidation Biomarker, 8-oxo-7,8-dihydro-2&amp;#8217;-deoxyguanosine, in Cultured Cells and Animal Tissues

L&#39;obiettivo di questo protocollo è il rilevamento del marker dell&#39;ossidazione DNA, 8-oxo-7,8-diidro-2&#39;-deossiguanosina (8-oxo-dGuo) mediante HPLC-DE, DNA da cellule o tessuti animali.

HPLC Misurazione del DNA ossidazione Biomarker, 8-oxo-7,8-diidro-2&#39;-deossiguanosina, in colture cellulari e tessuti animali

Oxidative stress is associated with many physiological and pathological processes, as well as xenobiotic metabolism, leading to the oxidation of ...

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JoVE Journal

Chemistry

HPLC Measurement of the DNA Oxidation Biomarker, 8-oxo-7,8-dihydro-2&#8217;-deoxyguanosine, in Cultured Cells and Animal Tissues

26.1K Views.  Health Canada.  L'obiettivo di questo protocollo è il rilevamento del marker dell'ossidazione DNA, 8-oxo-7,8-diidro-2'-deossiguanosina (8-oxo-dGuo) mediante HPLC-DE, DNA da cellule o tessuti animali. 

Video: HPLC Measurement of the DNA Oxidation Biomarker, 8-oxo-7,8-dihydro-2&#8217;-deoxyguanosine, in Cultured Cells and Animal Tissues

Steady-state, Pre-steady-state, and Single-turnover Kinetic Measurement for DNA Glycosylase Activity

Human 8-oxoguanine DNA glycosylase (OGG1) excises the mutagenic oxidative DNA lesion 8-oxo-7,8-dihydroguanine (8-oxoG) from DNA. Kinetic characterization of OGG1 is undertaken to measure the rates of 8-oxoG excision and product release. When the OGG1 concentration is lower than substrate DNA, time courses of product formation are biphasic; a rapid exponential phase (i.e. burst) of product formation is followed by a linear steady-state phase. The initial burst of product formation corresponds to the concentration of enzyme properly engaged on the substrate, and the burst amplitude depends on the concentration of enzyme. The first-order rate constant of the burst corresponds to the intrinsic rate of 8-oxoG excision and the slower steady-state rate measures the rate of product release (product DNA dissociation rate constant, koff). Here, we describe steady-state, pre-steady-state, and single-turnover approaches to isolate and measure specific steps during OGG1 catalytic cycling. A fluorescent labeled lesion-containing oligonucleotide and purified OGG1 are used to facilitate precise kinetic measurements. Since low enzyme concentrations are used to make steady-state measurements, manual mixing of reagents and quenching of the reaction can be performed to ascertain the steady-state rate (koff). Additionally, extrapolation of the steady-state rate to a point on the ordinate at zero time indicates that a burst of product formation occurred during the first turnover (i.e. y-intercept is positive). The first-order rate constant of the exponential burst phase can be measured using a rapid mixing and quenching technique that examines the amount of product formed at short time intervals (&lt;1 sec) before the steady-state phase and corresponds to the rate of 8-oxoG excision (i.e. chemistry). The chemical step can also be measured using a single-turnover approach where catalytic cycling is prevented by saturating substrate DNA with enzyme (E&gt;S). These approaches can measure elementary rate constants that influence the efficiency of removal of a DNA lesion.

Time courses for the glycosylase activity of 8-oxoguanine DNA glycosylase are biphasic exhibiting a burst of product formation and a linear steady-state phase. Utilizing quench-flow techniques, the burst and the steady-state rates can be measured, which correspond to excision of 8-oxoguanine and release of the glycosylase from the product DNA, respectively.

Allo steady-state, Pre-steady-state, e Single-fatturato di misura cinetica per il DNA Glycosylase Activity

Human 8-oxoguanine DNA glycosylase (OGG1) excises the mutagenic oxidative DNA lesion 8-oxo-7,8-dihydroguanine (8-oxoG) from DNA. Kinetic characterization ...

Ricerca

Chimica

HPLC-based Assay to Monitor Extracellular Nucleotide/Nucleoside Metabolism in Human Chronic Lymphocytic Leukemia Cells

This method describes a sensitive, specific, reliable and reproducible reverse phase high-performance liquid chromatography (RP-HPLC) assay developed and validated for the quantification of extracellular purine nucleotides and nucleosides produced by purified chronic lymphocytic leukemia (CLL) cells under different culture conditions. The chromatographic separation of adenosine 5&#39;-monophosphate (AMP), adenosine (ADO) and inosine (INO) is performed at RT on a silica-based, reversed-phase column that is used for polar compound retention. The method includes a binary mobile phase, which consists of 7 mM ammonium acetate and acetonitrile with a flow rate of 1.00 ml/min. The eluates are monitored using a Photodiode Array UV detector set at 260 nm. A standard calibration curve is generated to calculate the equation for the analytical quantification of each purine compound. System control, data acquisition and analysis are then performed. Applying this protocol, AMP, INO and ADO elute at 7, 11 and 11.9 min, respectively, and the total run time for each sample is 20 min. This protocol may be applied to different cell types and cell lines (both suspension and adherent), using culture media as matrix. The advantages are easy and fast sample preparation and the requirement of a small amount of supernatant for analysis. Furthermore, the use of a serum-free medium allows skipping the protein precipitation step with acetonitrile that impacts the final concentration of purine compounds. One of the limitations of the method is the requirement of the equilibration column run before each single sample run, making the total run time of the experiment longer and preventing high throughput screening applications.

The protocol described here represents an easy and reproducible method that employs reverse phase high-performance liquid chromatography (RP-HPLC) to measure purine metabolism on chronic lymphocytic leukemia (CLL) cells cultured under different conditions.

HPLC-based test per monitorare extracellulare Nucleotide / nucleosidici metabolismo in cronica cellule umane leucemia linfocitica

This method describes a sensitive, specific, reliable and reproducible reverse phase high-performance liquid chromatography (RP-HPLC) assay developed and ...

Determining the Chemical Composition of Corrosion Inhibitor/Metal Interfaces with XPS: Minimizing Post Immersion Oxidation

An approach for acquiring more reliable X-ray photoelectron spectroscopy data from corrosion inhibitor/metal interfaces is described. More specifically, the focus is on metallic substrates immersed in acidic solutions containing organic corrosion inhibitors, as these systems can be particularly sensitive to oxidation following removal from solution. To minimize the likelihood of such degradation, samples are removed from solution within a glove box purged with inert gas, either N2 or Ar. The glove box is directly attached to the load-lock of the ultra-high vacuum X-ray photoelectron spectroscopy instrument, avoiding any exposure to the ambient laboratory atmosphere, and thus reducing the possibility of post immersion substrate oxidation. On this basis, one can be more certain that the X-ray photoelectron spectroscopy features observed are likely to be representative of the in situ submerged scenario, e.g. the oxidation state of the metal is not modified.

A protocol to avoid the oxidation of metallic substrates during sample transfer from an inhibited acidic solution to an X-ray photoelectron spectrometer is presented.

Determinare la composizione chimica di inibitore di corrosione Interfacce / metallo con XPS: Minimizzare post immersione Ossidazione

An approach for acquiring more reliable X-ray photoelectron spectroscopy data from corrosion inhibitor/metal interfaces is described. More specifically, ...

Fabrication and Testing of Photonic Thermometers

In recent years, a push for developing novel silicon photonic devices for telecommunications has generated a vast knowledge base that is now being leveraged for developing sophisticated photonic sensors. Silicon photonic sensors seek to exploit the strong confinement of light in nano-waveguides to transduce changes in physical state to changes in resonance frequency. In the case of thermometry, the thermo-optic coefficient, i.e., changes in refractive index due to temperature, causes the resonant frequency of the photonic device such as a Bragg grating to drift with temperature. We are developing a suite of photonic devices that leverage recent advances in telecom compatible light sources to fabricate cost-effective photonic temperature sensors, which can be deployed in a wide variety of settings ranging from controlled laboratory conditions, to the noisy environment of a factory floor or a residence. In this manuscript, we detail our protocol for the fabrication and testing of photonic thermometers.

We describe the process of fabrication and testing of photonic thermometers.

Fabbricazione e collaudo di termometri fotonici

In recent years, a push for developing novel silicon photonic devices for telecommunications has generated a vast knowledge base that is now being ...

Simultaneous Measurement of HDAC1 and HDAC6 Activity in HeLa Cells Using UHPLC-MS

The search for new histone deacetylase (HDAC) inhibitors is of increasing interest in drug discovery. Isoform selectivity has been in the spotlight since the approval of romidepsin, a class I HDAC inhibitor for cancer therapy, and the clinical investigation of HDAC6-specific inhibitors for multiple myeloma. The present method is used to determine the inhibitory activity of test compounds on HDAC1 and HDAC6 in cells. The isoform activity is measured using the ultra-high-performance liquid chromatography &#8211; mass spectrometry (UHPLC-MS) analysis of specific substrates incubated with treated and untreated HeLa cells. The method has the advantage of reflecting the endogenous HDAC activity within the cell environment, in contrast to cell-free biochemical assays conducted on isolated isoforms. Moreover, because it is based on the quantification of synthetic substrates, the method does not require the antibody recognition of endogenous acetylated proteins. It is easily adaptable to several cell lines and an automated process. The method has already proved useful in finding HDAC6-selective compounds in neuroblasts. Representative results are shown here with the standard HDAC inhibitors trichostatin A (non-specific), MS275 (HDAC1-specific), and tubastatin A (HDAC6-specific) using HeLa cells.

The present method serves to identify isoform-specific inhibitors of histone deacetylases (HDAC) in HeLa cells by the UHPLC-MS analysis of multiple substrates. This is an antibody-free method developed to reflect HDAC1 and HDAC6 activity in the living cell environment, in contrast to single-isoform cell-free assays.

Misura simultanea di HDAC1 e HDAC6 attività in HeLa Cells utilizzando UHPLC-MS

The search for new histone deacetylase (HDAC) inhibitors is of increasing interest in drug discovery. Isoform selectivity has been in the spotlight since ...

DNA-magnetic Particle Binding Analysis by Dynamic and Electrophoretic Light Scattering

Isolation of DNA using magnetic particles is a field of high importance in biotechnology and molecular biology research. This protocol describes the evaluation of DNA-magnetic particles binding via dynamic light scattering (DLS) and electrophoretic light scattering (ELS). Analysis by DLS provides valuable information on the physicochemical properties of particles including particle size, polydispersity, and zeta potential. The latter describes the surface charge of the particle which plays major role in electrostatic binding of materials such as DNA. Here, a comparative analysis exploits three chemical modifications of nanoparticles and microparticles and their effects on DNA binding and elution. Chemical modifications by branched polyethylenimine, tetraethyl orthosilicate and (3-aminopropyl)triethoxysilane are investigated. Since DNA exhibits a negative charge, it is expected that zeta potential of particle surface will decrease upon binding of DNA. Forming of clusters should also affect particle size. In order to investigate the efficiency of these particles in isolation and elution of DNA, the particles are mixed with DNA in low pH (~6), high ionic strength and dehydration environment. Particles are washed on magnet and then DNA is eluted by Tris-HCl buffer (pH = 8). DNA copy number is estimated using quantitative polymerase chain reaction (PCR). Zeta potential, particle size, polydispersity and quantitative PCR data are evaluated and compared. DLS is an insightful and supporting method of analysis that adds a new perspective to the process of screening of particles for DNA isolation.

This protocol describes the synthesis of magnetic particles and evaluation of their DNA-binding properties via dynamic and electrophoretic light scattering. This method focuses on monitoring changes in particle size, their polydispersity and zeta potential of particle surface which play major role in binding of materials such as DNA.

DNA-magnetoscopico associazione analisi di dispersione della luce dinamica ed elettroforetica

Isolation of DNA using magnetic particles is a field of high importance in biotechnology and molecular biology research. This protocol describes the ...

Disentangling High Strength Copolymer Aramid Fibers to Enable the Determination of Their Mechanical Properties

Traditionally, soft body armor has been made from poly(p-phenylene terephthalamide) (PPTA) and ultra-high molecular weight polyethylene. However, to diversify the fiber choices in the United States body armor market, copolymer fibers based on the combination of 5-amino-2-(p-aminophenyl) benzimidazole (PBIA) and the more conventional PPTA were introduced. Little is known regarding the long-term stability of these fibers, but as condensation polymers, they are expected to have potential sensitivity to moisture and humidity. Therefore, characterizing the strength of the materials and understanding their vulnerability to environmental conditions is important for evaluating their use lifetime in safety applications. Ballistic resistance and other critical structural properties of these fibers are predicated on their strength. To accurately determine the strength of the individual fibers, it is necessary to disentangle them from the yarn without introducing any damage. Three aramid-based copolymer fibers were selected for the study. The fibers were washed with acetone followed by methanol to remove an organic coating that held the individual fibers in each yarn bundle together. This coating makes it difficult to separate single fibers from the yarn bundle for mechanical testing without damaging the fibers and affecting their strength. After washing, fourier transform infrared (FTIR) spectroscopy was performed on both washed and unwashed samples and the results were compared. This experiment has shown that there are no significant variations in the spectra of poly(p-phenylene-benzimidazole-terephthalamide-co-p-phenylene terephthalamide) (PBIA-co-PPTA1) and PBIA-co-PPTA3 after washing, and only a small variation in intensity for PBIA. This indicates that the acetone and methanol rinses are not adversely affecting the fibers and causing chemical degradation. Additionally, single fiber tensile testing was performed on the washed fibers to characterize their initial tensile strength and strain to failure, and compare those to other reported values. Iterative procedural development was necessary to find a successful method for performing tensile testing on these fibers.

The primary goal of the study is to develop a protocol to prepare consistent specimens for accurate mechanical testing of high strength copolymer aramid fibers, by removing a coating and disentangling the individual fiber strands without introducing significant chemical or physical degradation.

Districante fibre di aramide copolimero ad alta resistenza per consentire la determinazione delle loro proprietà meccaniche

Traditionally, soft body armor has been made from poly(p-phenylene terephthalamide) (PPTA) and ultra-high molecular weight polyethylene. However, to ...

Technical Aspect of the Automated Synthesis and Real-Time Kinetic Evaluation of [11C]SNAP-7941

Positron emission tomography (PET) is an essential molecular imaging technique providing insights into pathways and using specific targeted radioligands for in vivo investigations. Within this protocol, a robust and reliable remote-controlled radiosynthesis of [11C]SNAP-7941, an antagonist to the melanin-concentrating hormone receptor 1, is described. The radiosynthesis starts with cyclotron produced [11C]CO2 that is subsequently further reacted via a gas-phase transition to [11C]CH3OTf. Then, this reactive intermediate is introduced to the precursor solution and forms the respective radiotracer. Chemical as well as the radiochemical purity are determined by means of RP-HPLC, routinely implemented in the radiopharmaceutical quality control process. Additionally, the molar activity is calculated as it is a necessity for the following real-time kinetic investigations. Furthermore, [11C]SNAP-7941 is applied to MDCKII-WT and MDCKII-hMDR1 cells for evaluating the impact of P-glycoprotein (P-gp) expression on cell accumulation. For this reason, the P-gp expressing cell line (MDCKII-hMDR1) is either used without or with blocking prior to experiments by means of the P-gp substrate (&#177;)-verapamil and the results are compared to the ones observed for the wildtype cells. The overall experimental approach demonstrates the importance of a precise time-management that is essential for every preclinical and clinical study using PET tracers radiolabelled with short-lived nuclides, such as carbon-11 (half-life: 20 min).

Technical Aspect of the Automated Synthesis and Real-Time Kinetic Evaluation of [11C]SNAP-7941

Here, we represent a protocol for the fully automated radiolabelling of [11C]SNAP-7941 and the analysis of the real-time kinetics of this PET-tracer on P-gp expressing and non-expressing cells.

Aspetto tecnico della sintesi automatizzata e valutazione cinetica in tempo reale di [11C]SNAP-7941

Positron emission tomography (PET) is an essential molecular imaging technique providing insights into pathways and using specific targeted radioligands ...

Quantitative Atomic-Site Analysis of Functional Dopants/Point Defects in Crystalline Materials by Electron-Channeling-Enhanced Microanalysis

A novel elemental and chemical analysis scheme based on electron-channeling phenomena in crystalline materials is introduced, where the incident high-energy electron beam is rocked with the submicrometric pivot point fixed on a specimen. This method enables us to quantitatively derive the site occupancies and site-dependent chemical information of impurities or intentionally doped functional elements in a specimen, using energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy attached to a scanning transmission electron microscope, which is of significant interest to current materials science, particularly related to nanotechnologies. This scheme is applicable to any combination of elements even when the conventional Rietveld analysis by X-ray or neutron diffraction occasionally fails to provide the desired results because of limited sample sizes and close scattering factors of neighboring elements in the periodic table. In this methodological article, we demonstrate the basic experimental procedure and analysis method of the present beam-rocking microanalysis.

We provide a general outline of quantitative microanalysis methods for estimating the site occupancies of impurities and their chemical states by taking advantage of electron-channeling phenomena under incident electron beam-rocking conditions, which reliably extract information from minority species, light elements, oxygen vacancies, and other point/line/planar defects.

Analisi quantitativa del sito atomico dei difetti funzionali dei droganti/punti nei materiali cristallini mediante microanalisi potenziata dal canale elettronico

A novel elemental and chemical analysis scheme based on electron-channeling phenomena in crystalline materials is introduced, where the incident ...

HPLC Coupled with Chemical Fingerprinting for Multi-Pattern Recognition for Identifying the Authenticity of Clematidis Armandii Caulis

A method for identifying Chinese medicinal materials and their related adulterants was constructed by taking Clematidis Armandii Caulis (Chuanmutong, a universally used traditional Chinese medicine) as an example. Ten batches of genuine Chuanmutong varieties and five batches of related adulterants were analyzed and compared based on the high-performance liquid chromatography (HPLC) fingerprints combined with chemometrics, including cluster analysis (CA), principal component analysis (PCA), and orthogonal partial least-squares discrimination analysis (OPLS-DA). In addition, the content of &#946;-sitosterol was determined. The control chemical fingerprint of Chuanmutong was established, and 12 common peaks were identified. The similarity between the fingerprint of 10 batches of genuine Chuanmutong varieties and the control fingerprint was 0.910-0.989, while the similarity of five batches of adulterants was only 0.133-0.720. Based on the common peaks in the chromatogram, 15 batches of samples were classified into three content levels by PCA, and were aggregated into four categories by CA, achieving a clear distinction between authentic Chuanmutong and adulterants of Chuanmutong. Further, seven differential components that can effectively identify authentic Chuanmutong and adulterants of Chuanmutong were found through OPLS-DA. The &#946;-sitosterol content of 10 batches of genuine Chuanmutong varieties was 97.53-161.56 &#181;g/g, while the &#946;-sitosterol content of the five batches of adulterants varied greatly, among which the &#946;-sitosterol content of Clematis peterae Hand.-Mazz. and Clematis gouriana Roxb. Var. finetii Rehd. et Wils. was significantly lower than that of authentic varieties of Chuanmutong. The HPLC index component content and chemical fingerprint multi-pattern recognition method established in this study provide a new strategy for effectively identifying authentic Chinese medicinal materials and related adulterants.

HPLC Coupled with Chemical Fingerprinting for Multi-Pattern Recognition for Identifying the Authenticity of Clematidis Armandii Caulis

Here, we present a protocol to establish high-performance liquid chromatography (HPLC), coupled with chemical fingerprint multi-pattern recognition, which provides a new strategy for effectively identifying the genuine varieties of Clematidis Armandii Caulis and its adulterants.

HPLC accoppiato con impronte digitali chimiche per il riconoscimento multi-pattern per identificare l'autenticità di Clematidis armandii caulis

A method for identifying Chinese medicinal materials and their related adulterants was constructed by taking Clematidis Armandii Caulis (Chuanmutong, a ...