This work were supported by grants from National Key R&#38;D Program of China (2017YFC1103704), Shenzhen Foundation of Science and Technology (JCYJ20170817172116272), Special Funds for the Construction of High Level Hospitals in Guangdong Province (2019), Sanming Project of Medicine in Shenzhen (SZSM201412020), Fund for High Level Medical Discipline Construction of Shenzhen (2016031638), Shenzhen Foundation of Health and Family Planning Commission (SZXJ2017021, SZXJ2018059).

All experiments were performed in accordance with the relevant guidelines and regulations of the Institutional Review Board of Shenzhen Second People&#39;s Hospital, First Af&#64257;liated Hospital of Shenzhen University.
1. Design porcine specific primers
<ol>
	<li>Perform whole-genome BLAST analysis to identify porcine specific genes that were different from those of humans, monkeys or mouse, using the software NCBI&#160;(www.ncbi.nlm.nih.gov).</li>
	<li>Design primers according to 19 pig-...

<ol>
	<li>Buchman, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+organ+failure.">Multiple organ failure.</a> Current Opinion In General Surgery. , 26-31 (1993).</li><li>Smith, M., Dominguez-Gil, B., Greer, D., Manara, A., Souter, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organ+donation+after+circulatory+death:+current+status+and+future+potential.">Organ donation after circulatory death: current status and future potential.</a> Intensive care medicine. 45 (3), 310-321 (2019).</li><li>Lopez-Fraga, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+needed+Convention+against+trafficking+in+human+organs.">A needed Convention against trafficking in human organs.</a> Lancet. 383 (9936), 2187-2189 (2014).</li><li>Sykes, M., Sachs, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transplanting+organs+from+pigs+to+humans.">Transplanting organs from pigs to humans.</a> Science immunology. 4 (41), 6298 (2019).</li><li>Reardon, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+life+for+pig-to-human+transplants.">New life for pig-to-human transplants.</a> Nature. 527 (7577), 152-154 (2015).</li><li>Song, Z., Cooper, D. K., Mou, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+and+Regulation+Profile+of+Mature+MicroRNA+in+the+Pig:+Relevance+to+Xenotransplantation.">Expression and Regulation Profile of Mature MicroRNA in the Pig: Relevance to Xenotransplantation.</a> BioMed Research International. 2018, 2983908 (2018).</li><li>Chung, 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=CD4(+)+/CD8(+)+T-cell+ratio+correlates+with+the+graft+fate+in+pig-to-non-human+primate+islet+xenotransplantation.">CD4(+) /CD8(+) T-cell ratio correlates with the graft fate in pig-to-non-human primate islet xenotransplantation.</a> Xenotransplantation. 27 (2), 12562 (2020).</li><li>Yoon, C. H., Choi, S. H., Lee, H. J., Kang, H. J., Kim, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Predictive+biomarkers+for+graft+rejection+in+pig-to-non-human+primate+corneal+xenotransplantation.">Predictive biomarkers for graft rejection in pig-to-non-human primate corneal xenotransplantation.</a> Xenotransplantation. 26 (4), 12515 (2019).</li><li>Agbor-Enoh, 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=Circulating+cell-free+DNA+as+a+biomarker+of+tissue+injury:+Assessment+in+a+cardiac+xenotransplantation+model.">Circulating cell-free DNA as a biomarker of tissue injury: Assessment in a cardiac xenotransplantation model.</a> The Journal of Heart and Lung Transplantation. 37 (8), 967-975 (2018).</li><li>Vito Dabbs, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Are+symptom+reports+useful+for+differentiating+between+acute+rejection+and+pulmonary+infection+after+lung+transplantation.">Are symptom reports useful for differentiating between acute rejection and pulmonary infection after lung transplantation.</a> Heart &amp; Lung. 33 (6), 372-380 (2004).</li><li>Miller, C. 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=Non-invasive+approaches+for+the+diagnosis+of+acute+cardiac+allograft+rejection.">Non-invasive approaches for the diagnosis of acute cardiac allograft rejection.</a> Heart. 99 (7), 445-453 (2013).</li><li>Mandel, P., Metais, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Les+acides+nucl&#233;iques+du+plasma+sanguin+chez+l'homme.">Les acides nucl&#233;iques du plasma sanguin chez l'homme.</a> Comptes Rendus des Seances de l Academie des Sciences. 142 (3-4), 241-243 (1948).</li><li>Okkonen, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasma+cell-free+DNA+in+patients+needing+mechanical+ventilation.">Plasma cell-free DNA in patients needing mechanical ventilation.</a> Critical Care. 15 (4), 196 (2011).</li><li>Wagner, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Free+DNA--new+potential+analyte+in+clinical+laboratory+diagnostics.">Free DNA--new potential analyte in clinical laboratory diagnostics.</a> Biochemia Medica. 22 (1), 24-38 (2012).</li><li>Schwarzenbach, H., Nishida, N., Calin, G. A., Pantel, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+relevance+of+circulating+cell-free+microRNAs+in+cancer.">Clinical relevance of circulating cell-free microRNAs in cancer.</a> Nature Reviews Clinical Oncology. 11 (3), 145-156 (2014).</li><li>Mohiuddin, M. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chimeric+2C10R4+anti-CD40+antibody+therapy+is+critical+for+long-term+survival+of+GTKO.hCD46.hTBM+pig-to-primate+cardiac+xenograft.">Chimeric 2C10R4 anti-CD40 antibody therapy is critical for long-term survival of GTKO.hCD46.hTBM pig-to-primate cardiac xenograft.</a> Nature Communications. 7, 11138 (2016).</li><li>Bettegowda, 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=Detection+of+circulating+tumor+DNA+in+early-+and+late-stage+human+malignancies.">Detection of circulating tumor DNA in early- and late-stage human malignancies.</a> Science Translational Medicine. 6 (224), 24 (2014).</li><li>Dawson, S. 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=Analysis+of+circulating+tumor+DNA+to+monitor+metastatic+breast+cancer.">Analysis of circulating tumor DNA to monitor metastatic breast cancer.</a> New England Journal of Medicine. 368 (13), 1199-1209 (2013).</li><li>Newman, A. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+ultrasensitive+method+for+quantitating+circulating+tumor+DNA+with+broad+patient+coverage.">An ultrasensitive method for quantitating circulating tumor DNA with broad patient coverage.</a> Nature Medicine. 20 (5), 548-554 (2014).</li><li>Snyder, T. M., Khush, K. K., Valantine, H. A., Quake, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Universal+noninvasive+detection+of+solid+organ+transplant+rejection.">Universal noninvasive detection of solid organ transplant rejection.</a> Proceedings of the National Academy of Sciences of the United States of America. 108 (15), 6229-6234 (2011).</li><li>De Vlaminck, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+monitoring+of+infection+and+rejection+after+lung+transplantation.">Noninvasive monitoring of infection and rejection after lung transplantation.</a> Proceedings of the National Academy of Sciences of the United States of America. 112 (43), 13336-13341 (2015).</li><li>Zhou, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circulating+pig-specific+DNA+as+a+novel+biomarker+for+monitoring+xenograft+rejection.">Circulating pig-specific DNA as a novel biomarker for monitoring xenograft rejection.</a> Xenotransplantation. 26 (4), 12522 (2019).</li><li>Huo, Q., 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=Circulating+mi+RNA+or+circulating+DNA+&#8212;Potential+biomarkers+for+organ+transplant+rejection.">Circulating mi RNA or circulating DNA &#8212;Potential biomarkers for organ transplant rejection.</a> Xenotransplantation. 26 (1), 12444 (2019).</li><li>Gadi, V. K., Nelson, J. L., Boespflug, N. D., Guthrie, K. A., Kuhr, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Soluble+donor+DNA+concentrations+in+recipient+serum+correlate+with+pancreas-kidney+rejection.">Soluble donor DNA concentrations in recipient serum correlate with pancreas-kidney rejection.</a> Clinical Chemistry. 52 (3), 379-382 (2006).</li></ol>

Quantifying porcine circulating DNA represents a feasible approach to monitor the immune rejection of xenotransplantation. Gadi et al.24 found that donor-derived circulating DNA (ddcfDNA) content in the blood of patients with acute rejection was significantly higher than that of patients without rejection. These studies suggest that ddcfDNA may be a common biomarker for monitoring organ graft damage. In recent years, qPCR has increasingly been applied to the analysis of nucleic acids because of it...

Organ failure is one of the main causes of death1. Transplantation of cells, tissues and organs is an effective way to treat organ failure2. Nevertheless, the shortage of donor organs limits the clinical application of this method3,4. Studies have shown that pigs can be used as a potential source of human organs for clinical transplantation5,6. However, cross-species organ transplantation faces dangerous immune rejection. Therefore, it is crucial to monitor the immune rejection of xenotransplantation. Currently, clinical monitoring of immune rejection depends mainly on the patient&#39;s signs and symptoms, as well as laboratory tests (e.g., biopsy, immunobiochemical analysis, and ultrasound)7,8,9. However, these monitoring methods have many disadvantages. The signs and symptoms of immune rejection in patients usually appear late10, which is not conducive to early detection and early intervention; biopsy has the disadvantage of being invasive11, which is not easy for patients to accept; immunobiochemical analysis lacks sensitivity or specificity, and ultrasound is auxiliary and expensive. Therefore, it is urgent to find an effective and convenient method to monitor the immune rejection.
Circulating DNA is an extracellular type of DNA found in blood. Mandel and Metais12 first reported the presence of circulating DNA in peripheral blood in 1948. Under normal physiological conditions, circulating DNA in the blood of healthy people is relatively low at baseline. However, in some pathologies, such as tumors, myocardial infarction, autoimmune diseases, and transplant rejection, the level of circulating DNA in the blood can be significantly increased13,14 due to the massive release of circulating DNA caused by apoptosis and necrosis. The origin of circulating DNA is associated with apoptosis and necrosis15, which are characteristic of xenograft rejection16.
Circulating DNA has been proven to be a minimally-invasive biomarker for detecting cancers17,18,19. High through-put sequencing of donor-derived circulating DNA is reliable for the detection of rejection after organ transplantation20,21. However, this method requires a high concentration and quality of extracted DNA. The DNA requirements in addition to the high cost and time-consumption make this method ineligible for routine clinical use. Donor-derived circulating DNA can be precisely quantified by quantitative real-time PCR (qPCR), which is both specific and sensitive. Therefore, quantifying porcine circulating DNA by qPCR is a feasible method to monitor the immune rejection of xenotransplantation. This is less invasive, highly sensitive and specific, low cost, and time-saving. Pigs and human beings are genetically separate with quite different genomic sequences (Figure 1). Therefore, circulating porcine DNA can be released into the recipient&#39;s blood post-xenotransplantation because of xeno-rejection. CpsDNA could be precisely quantified by qPCR with species-specific primers in the recipient&#8217;s blood. Previously, we have demonstrated the rationale and feasibility of cpsDNA as a biomarker for xenotransplantation22,23. Here, we disclose more experimental tips and details. The experiment consists of the following steps. Firstly, porcine specific primers were designed, and genomic DNA was isolated, which were used to verify the specificity of the primers by regular PCR. Secondly, constructing the standard curve of cpsDNA and isolating cpsDNA from the sample blood. Finally, the circulating pig-specific DNA was quantified using&#160;qPCR.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr >
			<td ><a>Agarose</a></td>
			<td >Biowest, Barcelona, Spain</td>
			<td >111860</td>
			<td ></td>
		</tr>
		<tr >
			<td >BamHI-HF</td>
			<td >New England Biolabs, Ipswich, Mass, USA</td>
			<td >R3136S</td>
			<td ></td>
		</tr>
		<tr >
			<td >1.5 mL microcentrifuge tube</td>
			<td >Axygen&#160;Biosciences, Union City, CA, USA</td>
			<td >MCT-150-C</td>
			<td ></td>
		</tr>
		<tr >
			<td >0.2 mL PCR tube</td>
			<td >Axygen&#160;Biosciences, Union City, CA, USA</td>
			<td >PCR-02-C</td>
			<td ></td>
		</tr>
		<tr >
			<td >C57BL/6 Mice</td>
			<td >Medical Animal Center of Guangdong Province,&#160; China</td>
			<td ></td>
			<td >8~10 weeks</td>
		</tr>
		<tr >
			<td >Centrifuge</td>
			<td >Thermo&#160;Fisher&#160;Scientific, Walt- ham, MA, USA</td>
			<td >Micro 21R</td>
			<td ></td>
		</tr>
		<tr >
			<td >2-Log DNA Ladder</td>
			<td >New England Biolabs, Ipswich, Mass, USA</td>
			<td >N3200S</td>
			<td >0.1&#8211;10.0 kb</td>
		</tr>
		<tr >
			<td >Marker I&#160;</td>
			<td >Tiangen, Beijing, China</td>
			<td >MD101-02</td>
			<td >0.1&#8211;0.6 kb</td>
		</tr>
		<tr >
			<td >DNA Mini Column(HiBind DNA Mini Columns)</td>
			<td >Omega Bio-tek, Norcross, GA, USA</td>
			<td >DNACOL-01</td>
			<td ></td>
		</tr>
		<tr >
			<td >DNA loading buffer</td>
			<td >Solarbio, Beijing, China</td>
			<td >D1010</td>
			<td ></td>
		</tr>
		<tr >
			<td rowspan="2" >E.Z.N.A.Plasmid DNA Mini Kit I and E.Z.N.A. Plasmid DNA Mini Kit II</td>
			<td rowspan="2" >Omega Bio-tek, Norcross, GA, USA</td>
			<td >D6942</td>
			<td rowspan="2" ></td>
		</tr>
		<tr >
			<td >D6943</td>
		</tr>
		<tr >
			<td >EcoR I</td>
			<td >Takara&#160;Bio, Shiga, Japan</td>
			<td >&#160;1040S</td>
			<td ></td>
		</tr>
		<tr >
			<td >Female Bama mini pigs</td>
			<td >BGI Ark Biotechnology, Shenzhen, China</td>
			<td ></td>
			<td >2~4 months</td>
		</tr>
		<tr >
			<td >Genomic DNA Extraction Kit &#8544;</td>
			<td >Tiangen, Beijing, China</td>
			<td >DP304-02</td>
			<td ></td>
		</tr>
		<tr >
			<td >SYBR Green Realtime PCR Master Mix</td>
			<td >Toyobo, Osaka, Japan</td>
			<td >QPK-201</td>
			<td ></td>
		</tr>
		<tr >
			<td >Gel Doc XR</td>
			<td >Bio-Rad, Hercules, USA</td>
			<td ></td>
			<td ></td>
		</tr>
		<tr >
			<td >Male cynomolgus monkeys</td>
			<td >Guangdong Landau Biotechnology, Guangzhou, China</td>
			<td ></td>
			<td >8 years</td>
		</tr>
		<tr >
			<td >Nucleic acid dye(Gelred)</td>
			<td >Biotium, Fremont, USA</td>
			<td >42003</td>
			<td ></td>
		</tr>
		<tr >
			<td >polymerase(Premix Taq)</td>
			<td >Takara&#160;Bio, Shiga, Japan</td>
			<td >RR901A</td>
			<td ></td>
		</tr>
		<tr >
			<td >pMD19-T plasmid</td>
			<td >Takara&#160;Bio, Shiga, Japan</td>
			<td >D102A</td>
			<td ></td>
		</tr>
		<tr >
			<td >qPCR machine</td>
			<td >Applied Biosystems QSDx, Waltham, USA</td>
			<td ></td>
			<td ></td>
		</tr>
		<tr >
			<td >Serum/Circulating DNA Extraction Kit</td>
			<td >Tiangen, Beijing, China</td>
			<td >DP339</td>
			<td ></td>
		</tr>
		<tr >
			<td >TAE</td>
			<td >sangon Biotech, Shanghai, China</td>
			<td >B548101</td>
			<td ></td>
		</tr>
	</tbody>
</table>

quantification of circulating pig-specific dna in the blood of a xenotransplantation model

Xenotransplantation is a feasible method to treat organ failure. However, how to effectively monitor the immune rejection of xenotransplantation is a problem for physicians and researchers. This manuscript describes a simple and effective method to monitor immune rejection in pig-to-mouse cell transplantation models and pig-to-monkey artery patch transplantation models. Circulating DNA is a potentially non-invasive biomarker for organ damage. In this study, circulating pig-specific DNA (cpsDNA) was monitored during xenograft rejection by quantitative real-time PCR (qPCR). In this protocol, porcine specific primers were designed, plasmids-containing porcine specific DNA fragments were constructed, and standard curves for quantitation were established. Species-specific primers were then used to quantify cpsDNA by qPCR in pig-to-mouse cell transplantation models and pig-to-monkey artery patch transplantation models. The value of this method suggests that it can be used as a simple, convenient, low cost, and less invasive method to monitor the immune rejection of xenotransplantation.

In this protocol, porcine specific primers were designed, plasmids-containing porcine specific DNA fragments were constructed, and standard curves for quantitation were established (Figure 4). Species specificities of the 19 primers were confirmed by PCR. Species-specific primers (primer #4 and primer #11) were then used to quantify cpsDNA by qPCR in pig-to-mouse cell transplantation models and pig-to-monkey artery patch transplantation models.
Agarose electrophor...

Watch this Scientific Journal Video about Quantification of Circulating Pig-Specific DNA in the Blood of a Xenotransplantation Model at JoVE.com

Quantification of Circulating Pig-Specific DNA in the Blood of a Xenotransplantation Model

In this protocol, porcine specific primers were designed, plasmids-containing porcine specific DNA fragments were constructed, and standard curves for quantitation were established. Using species-specific primers, cpsDNA was quantified by qPCR in pig-to-mouse cell transplantation models and pig-to-monkey artery patch transplantation models.

Xenotransplantation is a feasible method to treat organ failure. However, how to effectively monitor the immune rejection of xenotransplantation is a ...

Xenotransplantation is a feasible method to to treat However, effective monitoring of the immune rejection of xenotransplantation is a problem for physicians and the researchers. This protocol is a simple, convenient, low cost and less invasive method to monitor the immune rejection of the xenotransmutation. This technique can be used in xenotransplantation field, including pig-to-human islet transplantation, kidney transplantation, liver transplantation and heart transplantation.Begin by transferring 500 microliters of blood samples into different micro centrifuge tubes. Add 20 microliters of protease K and 500 microliters of lysis buffer into the tubes. Then thoroughly shake them to mix.Put the tubes in a water bath at 56 degrees Celsius for 10 minutes, shaking them two to three times during the incubation until the solution becomes clear centrifuge them briefly to remove the liquid beads from the inner wall of the tube covers. Then add 500 microliters of Anhydrous, Ethyl Alcohol, and shake thoroughly. Transfer the mixture into the adsorption column.Then centrifuge the column for two minutes and discard the waste liquid. Add 800 microliters of rinse solution to each adsorption column, and centrifuge for one minute. leave the columns at room temperature for a few minutes to dry the remaining rinse solution.Transfer the absorption columns to a clean centrifugal tube. Add 50 microliters of elution buffer to the middle of the adsorption films and place them at room temperature for two to five minutes, then centrifuge them for one minute. Prepare the PCR master mix according to manuscript directions, then add 23 microliters of the mix into each 0.6 milliliter micro centrifuge tube.Add two microliters of genomic DNA to each tube and carefully Cabot. Then briefly mix and centrifuge. Place the tubes in a PCR cycler and start the amplification.When the reaction is finished perform Agarose electrophoresis. Add 1.2 grams of Agarose into a flask containing a hundred millimeters of TAE and boil it for five minutes in the microwave. Once the Agarose has cooled to approximately 70 degrees Celsius, add five microliters of nucleic acid dye into the flask, slowly, pour it into the plate and leave it at room temperature until it solidifies into a gel.Add five microliters of each sample and 2-Log DNA Ladder or DNA Marker 1, into the wells of the Agarose gel and electrophoresis at 120 million pier until the bands are separated. Visualize the gel with an ultraviolet imager. After performing transformation as described in the text manuscript, verify the plasmids by double restriction enzyme digestion with EcoR I and Bam HI.Separate the digested products with 1%Agarose electrophoresis and expose the gel to UV light.Dilute the concentrated plasmid with the fragment of porcine DNA to two times 10 to the 11th copies per milliliter for the starting standard solution, Using double distilled water. To establish a standard curve, prepare a qPCR master mix, as described in the text manuscript and add 40 microliters of the mix into each tube of an eight-tube strip. Add 10 microliters of standard DNA of different concentrations, cap the tubes then briefly mix and centrifuge them.Place the tubes in the qPCR machine and perform the amplification. Use EDTA tubes to collect blood samples of about 400 microliters from the pig-to-monkey artery patch models, or 100 microliters from the pig-to-mouse cell transplantation models. Then transfer the samples to 1.5 milliliter centrifuge tubes.Remove the blood cells from the blood samples by centrifugation at low temperature and high speed. Transfer the supernatant to a new 1.5 milliliters centrifuge tube and remove the cell debris by centrifugation at 16, 000 times G for 10 minutes. Transfer the supernatant to a new 1.5 milliliter centrifuge tube and extract the circulating DNA using a commercial serum while circulating DNA extraction kit.Condense the volume of circulating DNA to 40 microliters and store it at negative 20 degrees Celsius. Perform qPCR to quantify the circulating pig-specific DNA. Porcine-specific primers were designed and used to quantify circulating pig-specific DNA by qPCR, in pig-to-mouse cell transplantation models and pig-to-monkey artery patch, transplantation models.Agarose electrophoresis was used to isolate amplified DNA fragments. Using PCR, the primers-specific for amplified porcine genomic DNA were identified. Next, species specificities of these primers in the cohort of monkey or human genomic DNA or in the cohort of mouse genomic DNA, were confirmed.Finally two species-specific primers, were used to amplify pig DNA in the pig-to-monkey artery patch and pig to mouse, cell transplantation models. The most important thing to remember while attempting this protocol, is that contamination of all sorts should be prevented. This technique paves the way for researchers to explore new questions within xenotransplantation because it is a simple low-cost and non invasive method to monitor the immune rejection of xenotransplantation.

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3.9K vistas.  Shenzhen University School of Medicine, First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital. El xenotrasplante es un método factible para tratar Sin embargo, el monitoreo eficaz del rechazo inmune del xenotrasplante es un problema para los médicos y los investigadores. Este protocolo es un método simple, conveniente, de bajo costo y menos invasivo para monitorear el rechazo inmune de la xenotransmutación. Esta técnica se puede utilizar en el campo del xenotrasplante, incluyendo el trasplante de islote de cerdo a humano, trasplante de riñón, trasplante de hígado y trasplante d...