This work was supported by National Institutes of Health grant UC4 DK104166 (to RGM). We wish to acknowledge the assistance of the Indiana Diabetes Research Center Translation Core supported by National Institutes of Health grant P30 DK097512.

Ethics Statement: Protocols were approved by the Indiana University Institutional Review Board. Parents of subjects provided written informed consent, and children older than 7 years provided assent for their participation.
1. Serum Processing
NOTE: The assay as described has been rigorously tested using human serum isolated as follows.
<ol>
	<li>Collect blood in one red top (no-additive; uncoated) blood collection tube.</li>
	<li>Let sit at room temperature for 30 min to allow the clot to form.</li>
	<li>Centrifuge tube at 2,000 x g for 10 min at room temperature. Transfer the supernatant (serum) to a new tube designated for serum storage (polypropylene screw top tubes, size dependent on samples).</li>
	<li>Store samples at -80 &#186;C until ready for DNA isolation.</li>
</ol>
2. Serum DNA Extraction
NOTE: DNA is extracted with a DNA extraction kit using 50 &#181;l of serum (recommended), following manufacturer&#39;s protocol with some modifications.
<ol>
	<li>Prepare 200 &#181;l lysis buffer + 1 &#181;l poly(A) (5 &#181;g) per sample in an microcentrifuge tube. Vortex for 15 sec. Set aside until Step 2.3.</li>
	<li>Take serum samples from -80 &#186;C freezer and thaw at room temperature. Bring serum sample volume up to 200 &#181;l total using phosphate-buffered saline (PBS, with calcium chloride and magnesium chloride).</li>
	<li>Lyse the sample by adding 20 &#181;l protease (1.4 Anson units/ml) to sample, followed by 200 &#181;l lysis buffer/polyA mix (from Step 2.2) and vortex for 8 sec. Incubate sample at 56 &#176;C for 10 min, then briefly centrifuge for 7 sec at top speed in a microcentrifuge (&#62;10,000 x g).</li>
	<li>Precipitate DNA by adding 230 &#181;l 100% ethanol to sample and vortex for 8 sec. Briefly centrifuge for 7 sec at top speed (&#62;10,000 x g).</li>
	<li>Apply the DNA to the spin column by adding 600 &#181;l sample mixture to mini spin column. Centrifuge at 6,000 x g for 1 min. Discard the flow-through and place column in a clean tube.</li>
	<li>Wash the DNA by adding 500 &#181;l wash buffer 1 to the column. Centrifuge at 6,000 x g for 1 min. Discard the flow-through and place column in a clean tube. Add 500 &#181;l wash buffer 2 to column and centrifuge at top speed (&#62;10,000 x g) for 3 min. Place column in a new 1.5 ml microcentrifuge tube and centrifuge at top speed again for 1 min.</li>
	<li>Elute the DNA by placing column in a new 1.5 ml microcentrifuge tube and adding 60 &#181;l elution buffer directly on the filter. It is important to switch tips between samples to prevent cross contamination. Incubate at room temperature for 5 min, then centrifuge at 6,000 x&#160;g for 1 min. Add another 60&#160;&#956;l of elution buffer and centrifuge at 6,000 x g for 1 min.&#160;</li>
	<li>Store DNA at -20 &#186;C for later use, or proceed immediately to bisulfite conversion.</li>
</ol>
3. Bisulfite Conversion
NOTE: Bisulfite conversion is performed using a bisulfite conversion kit, following the manufacturer&#39;s protocol with some modifications.
<ol>
	<li>To convert unmethylated cytosines to uracils, add 130 &#181;l of bisulfite conversion reagent to 20 &#181;l of DNA from step 2.7 in a PCR tube (single 0.2 ml PCR tube or 8-strip PCR tubes). Save the remaining 40 &#181;l of DNA for future use, or use in replicate reactions. Mix 20 times by pipetting up and down and centrifuge briefly to make sure no drops are on sides or lid. Incubate in a water bath or thermal cycler as follows: 98 &#176;C for 8 min, 54 &#176;C for 60 min, 4 &#176;C for 5 min.
	<ol>
		<li>Proceed to step 3.2 or store at 4 &#176;C for up to 20 hr.</li>
	</ol>
	</li>
	<li>Add 600 &#181;l of binding buffer to spin column and place the column in the provided collection tube. Apply the bisulfited DNA to column and mix by pipetting up and down 10 times. Centrifuge at top speed (&#62;10,000 x g) for 30 sec. Discard flow-through.</li>
	<li>Wash DNA by adding 100 &#181;l of wash buffer to column and centrifuge at top speed (&#62;10,000 x g) for 30 sec.</li>
	<li>Perform desulphonation to remove sulphonate group to finalize the conversion of unmethylated cytosines to uracil by adding 200 &#181;l of desulphonation buffer to the column. Let stand at room temperature for 20 min, then centrifuge at top speed (&#62;10,000 x g) for 30 sec.</li>
	<li>Wash DNA by adding 200 &#181;l of wash buffer to the column and centrifuge at full speed for 30 sec. Discard the flow-through and repeat this wash step.</li>
	<li>Place the column into a 1.5 ml microcentrifuge tube. Elute DNA by adding 10 &#181;l elution buffer directly to column filter. Incubate for 1 min. Centrifuge for 30 s at full speed to elute DNA. Quantify recovered DNA by spectrophotometry at A260. 
	NOTE: The DNA detected by spectrophotometry represents primarily the carrier polyA DNA that was added at step 2.3 above. Typically, recovery of polyA is &#8805;85% of the input (&#62;4.25 &#181;g).</li>
	<li>Store DNA at -20 &#176;C until ready to proceed with digital PCR.</li>
</ol>
4. Multiplex Digital PCR
<ol>
	<li>Make a master mix with enough solution for each sample and control. Include at least one sample containing water (negative control), one sample of a plasmid containing unmethylated INS (1 pg, positive control), one sample of plasmid containing methylated INS (1 pg, positive control), and one sample containing a 1:1 mixture of plasmids.
	<ol>
		<li>To prepare the PCR master mix, add 12.5 &#181;l per reaction of PCR buffer (e.g., 125 &#181;l per 10 samples), 1.25 &#181;l per reaction primer/probe mix (e.g., 12.5 &#181;l per 10 samples), 8.25 &#181;l per reaction water (e.g., 82.5 &#181;l per 10 samples), 0.5 &#181;l per reaction EcoR1 enzyme (e.g., 5 &#181;l per 10 samples). 
		NOTE: Primers and probes used here are as follows: Forward Primer: 5&#39;-GGAAATTGTAGTTTTAGTTTTTAGTTATTTGT-3&#39;; Reverse Primer: 5&#39;-AAAACCCATCTCCCCTACCTATCA-3&#39;; FAM probe: FAM-5&#39;-ACCCCTACCACCTAAC-3&#39;-MGB; VIC probe: VIC-5&#39;-ACCCCTACCGCCTAAC-3&#39;-MGB.</li>
	</ol>
	</li>
	<li>Set up multiplex PCR reaction in a 96-well plate. Add 19.5 &#181;l of master mix to each well. Add 2.5 &#181;l of bisulfite converted DNA sample into each appropriate well (save the remaining 7.5 &#181;l of bisulfite converted DNA or use in replicate reactions). Mix by pipetting up and down several times. 
	NOTE: All 8 wells in a row must contain sample or buffer control.</li>
	<li>Seal with a foil seal using a plate sealer and centrifuge in a plate spinner until there is no liquid on the sides of the wells.</li>
	<li>Set up the automated droplet generator on the touchscreen. 
	NOTE: All 8 wells in the cartridge must contain sample or buffer control.
	<ol>
		<li>Set the number of rows being used by touching the row(s) in which samples are loaded into on the 96-well plate from step 4.2 and highlight the row in blue to indicate an active row.</li>
		<li>Load consumables from back to front to avoid contamination. To start, add cartridges along the back row of the instrument. Load tips into center row of the instrument. 
		NOTE: The cartridges can only fit into the holders in the correct orientation.</li>
		<li>Place 96-well plate into the instrument. Remove a cold block from -20 &#176;C freezer and place a new skirted 96-well plate into it. Place it inside the instrument next to the sample loaded 96-well plate.</li>
		<li>Add oil to dispenser in the front of the instrument. Select type of oil on touchscreen.</li>
		<li>Touch the blue start button to start the run. Confirm plate setup and touch start run button to begin.</li>
	</ol>
	</li>
	<li>Once finished, remove the 96-well plate that contains the newly formed droplets and seal with a foil seal using a plate sealer.</li>
	<li>Perform PCR10 on a thermal cycler using the following program: 95 &#176;C for 10:00 min; 40 cycles at: 94 &#176;C for 00:30 min, 57.5 &#176;C for 01:00 min; 98 &#176;C for 10:00 min; 12 &#176;C for 10 min or up to 24 hr.</li>
	<li>Place the plate on the droplet reader and set up the reader.
	<ol>
		<li>Click on the setup tab. Open a new template by clicking template &#62; new. Enter a file name.</li>
		<li>Use the well editor to set the parameters for each sample. Give each sample a unique name, set experiment to Rare Event Detection (R-RED), and set master mix to the mix used in step 4.1.</li>
		<li>Give Target 1 a name (i.e., unmethylated) and set Target 1 as unknown (U). Give Target 2 a name (i.e., methylated) and set Target 2 as reference (R).</li>
		<li>Click Run tab to start the run. In the run options window, select the detection chemistry (FAM/VIC).</li>
	</ol>
	</li>
</ol>
5. Data Analysis
<ol>
	<li>Open results in analyze tab and analyze using 2-D plot based on positive controls (see Figure 1).</li>
	<li>Export CSV file generated by droplet reader to a spreadsheet program for data analysis.</li>
	<li>To generate &#34;copies per &#181;l&#34; of serum, use the formula: (concentration*250)/(volume of serum used for DNA isolation in &#181;l).6 
	NOTE: The data is typically converted to log10 when acquired from human serum to ensure normal distribution. Alternatively, data can be plotted on a log10 scale and analyzed by non-parametric statistics.</li>
</ol>
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span.s1 {font: 16.0px Calibri}
</style>

<ol>
	<li>Lehuen, A., Diana, J., Zaccone, P., Cooke, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immune+cell+crosstalk+in+type+1+diabetes.">Immune cell crosstalk in type 1 diabetes.</a> Nat. Rev. Immunol. 10 (7), 501-513 (2010).</li><li>Sherry, N. A., Tsai, E. B., Herold, K. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Natural+history+of+beta-cell+function+in+type+1+diabetes.">Natural history of beta-cell function in type 1 diabetes.</a> Diabetes. 54, 32-39 (2005).</li><li>Maganti, A., Evans-Molina, C., Mirmira, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+immunobiology+to+&#946;-cell+biology:+the+changing+perspective+on+type+1+diabetes.">From immunobiology to &#946;-cell biology: the changing perspective on type 1 diabetes.</a> Islets. 6 (2), 28778 (2014).</li><li>Matthews, J. B., Staeva, T. P., Bernstein, P. L., Peakman, M., von Herrath, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ITN-JDRF+Type+1+Diabetes+Combination+Therapy+Assessment+Group+Developing+combination+immunotherapies+for+type+1+diabetes:+recommendations+from+the+ITN-JDRF+Type+1+Diabetes+Combination+Therapy+Assessment+Group.">ITN-JDRF Type 1 Diabetes Combination Therapy Assessment Group Developing combination immunotherapies for type 1 diabetes: recommendations from the ITN-JDRF Type 1 Diabetes Combination Therapy Assessment Group.</a> Clin. Exp. Immunol. 160 (2), 176-184 (2010).</li><li>. Human Islet Research Network | HIRN Available from: <a target="_blank" href="https://hirnetwork.org/">https://hirnetwork.org/</a> (2016)</li><li>Fisher, M. M., Watkins, R. 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=Elevations+in+Circulating+Methylated+and+Unmethylated+Preproinsulin+DNA+in+New-Onset+Type+1+Diabetes.">Elevations in Circulating Methylated and Unmethylated Preproinsulin DNA in New-Onset Type 1 Diabetes.</a> Diabetes. 64 (11), 3867-3872 (2015).</li><li>Husseiny, M. I., Kaye, A., Zebadua, E., Kandeel, F., Ferreri, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue-Specific+Methylation+of+Human+Insulin+Gene+and+PCR+Assay+for+Monitoring+Beta+Cell+Death.">Tissue-Specific Methylation of Human Insulin Gene and PCR Assay for Monitoring Beta Cell Death.</a> PLoS ONE. 9 (4), 94591 (2014).</li><li>Herold, K. C., Usmani-Brown, 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=&#946;+cell+death+and+dysfunction+during+type+1+diabetes+development+in+at-risk+individuals.">&#946; cell death and dysfunction during type 1 diabetes development in at-risk individuals.</a> J. Clin. Invest. 125 (3), 1163-1173 (2015).</li><li>Lehmann-Werman, R., Neiman, 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=Identification+of+tissue-specific+cell+death+using+methylation+patterns+of+circulating+DNA.">Identification of tissue-specific cell death using methylation patterns of circulating DNA.</a> Proc. Natl. Acad. Sci. U.S.A. 113 (13), 1826-1834 (2016).</li><li>Saiki, R. K., Gelfand, D. 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=Primer-directed+enzymatic+amplification+of+DNA+with+a+thermostable+DNA+polymerase.">Primer-directed enzymatic amplification of DNA with a thermostable DNA polymerase.</a> Science. 239 (4839), 487-491 (1988).</li><li>Kuroda, A., Rauch, T. 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=Insulin+gene+expression+is+regulated+by+DNA+methylation.">Insulin gene expression is regulated by DNA methylation.</a> PloS One. 4 (9), 6953 (2009).</li><li>Akirav, E. M., Lebastchi, 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=Detection+of+&#946;+cell+death+in+diabetes+using+differentially+methylated+circulating+DNA.">Detection of &#946; cell death in diabetes using differentially methylated circulating DNA.</a> Proc. Natl. Acad. Sci. U.S.A. 108 (47), 19018-19023 (2011).</li><li>Fisher, M. M., Perez Chumbiauca, C. N., Mather, K. J., Mirmira, R. G., Tersey, S. A. <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+islet+&#946;-cell+death+in+vivo+by+multiplex+PCR+analysis+of+differentially+methylated+DNA.">Detection of islet &#946;-cell death in vivo by multiplex PCR analysis of differentially methylated DNA.</a> Endocrinology. 154 (9), 3476-3481 (2013).</li><li>Patterson, K., Molloy, L., Qu, W., Clark, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA+methylation:+bisulphite+modification+and+analysis.">DNA methylation: bisulphite modification and analysis.</a> J. Vis. Exp. (56), (2011).</li><li>Derks, S., Lentjes, M. H. F. M., Hellebrekers, D. M. E. I., de Bru&#239;ne, A. P., Herman, J. G., van Engeland, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methylation-specific+PCR+unraveled.">Methylation-specific PCR unraveled.</a> Cell. Oncol. 26 (5-6), 291-299 (2004).</li><li>Husseiny, M. I., Kuroda, A., Kaye, A. N., Nair, I., Kandeel, F., Ferreri, K. <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+a+quantitative+methylation-specific+polymerase+chain+reaction+method+for+monitoring+beta+cell+death+in+type+1+diabetes.">Development of a quantitative methylation-specific polymerase chain reaction method for monitoring beta cell death in type 1 diabetes.</a> PloS One. 7 (10), 47942 (2012).</li><li>Hindson, B. J., Ness, K. 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=High-Throughput+Droplet+Digital+PCR+System+for+Absolute+Quantitation+of+DNA+Copy+Number.">High-Throughput Droplet Digital PCR System for Absolute Quantitation of DNA Copy Number.</a> Anal. Chem. 83 (22), 8604-8610 (2011).</li><li>Sozzi, G., Roz, L., 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=Effects+of+prolonged+storage+of+whole+plasma+or+isolated+plasma+DNA+on+the+results+of+circulating+DNA+quantification+assays.">Effects of prolonged storage of whole plasma or isolated plasma DNA on the results of circulating DNA quantification assays.</a> J. Natl. Cancer Inst. 97 (24), 1848-1850 (2005).</li></ol>

The authors have nothing to disclose.

DNA의 methyltransferases에 의해 시토신의 메틸화는 많은 유전자의 전사의 후생 유전 학적 제어 할 수 있습니다. 인간의 INS 유전자는 거의 독점적으로 세포 β 섬으로 표현, 그 전사 (11)의 침묵에 INS 유전자의 시토신 메틸화의 주파수 사이의 상관 관계가있을 나타납니다. 13 - 따라서, 대부분의 세포 유형은 세포를 11 β에 비해 다양한 사이토에서 INS 유전?...

제 1 형 당뇨병 (T1D)은 자기 반응성 T 세포를 1 β 세포의 인슐린 - 생성 췌장의 파괴를 특징으로하는자가 면역 질환이다. T1D의 진단은 일반적으로 인슐린 결핍의 증거로 케톤 산증으로 야기 될 수 있습니다 린, 젊은 개인에 고혈당 (혈당&gt; 200 밀리그램 / DL)의 측정에 따라 이루어집니다. T1D의 진단시, β 세포 기능 및 질량의 상당한 감소에 대한 증거가있다 (50 - 90 %)이. 임상 연구에서, 진단시 제정 된 여러 면역 조절 성 약물, 질병의 임상 적 관해 이어질 β 세포 기능 (그리고 아마도 질량), 그러나 아무도의 안정화 개발을위한 전화를 제기 한 연구 결과를 초래 질병의 초기 탐지와 대한 바이오 마커의 조합의 효과의 길이 추적 3,4 치료. 국제 컨소시엄의 노력, 이러한히스 (5)의 국립 연구소에서 인간의 작은 섬 연구 네트워크 컨소시엄이야, T1D의 β 세포 스트레스와 죽음에 초점 바이오 마커의 개발 필요성을 강조했다. 9 - 이러한 노력에 맞춰, 우리 그룹 등 최근 β 세포 6 죽어 주로 발생, 후 성적 변형 된 DNA 조각을 순환 측정 바이오 마커 분석을 개발했다. 지금까지 발표 된 검정 모두에서, 초점이 다른 세포 유형에 비해 코딩 및 프로모터 영역의 비 메틸화 된 CpG 부위의 큰 정도를 보여주는 인간 유전자 부호화 preproinsulin (INS)의 정량에있다. 메틸화 INS DNA 단편의 해방은 (괴사, 세포 사멸) β 세포를 죽음에서 주로 발생으로 가정 하였다. 우리의 최근의 연구는 청소년, 위치 -69 bp의에서 메틸화 및 메틸화 모두 INS의 DNA에 고도는 (상대가 마에 것으로 나타났다그는 새로운 발병 T1D에서 관찰되었다) 사이트를 시작, 함께이 인구 6과 같은 특정 바이오 마커를 제공 전사. 이러한 바이오 마커 분석이 분리 된 DNA의 중아 변환 다음에 상용 스핀 키트를 사용하여 혈청 또는 혈장에서 무 세포 DNA의 분리를 포함 (우라실에 비 메틸화 된 시토신을 변환하는 그대로 메틸화 된 시토신을 떠나). 이 보고서에서 우리는 차별적 메틸화 INS DNA에 대한 혈청 샘플 수집, 혈청에서 무 세포 DNA, 중아 변환 및 (이제부터는, 디지털 PCR) 방울 디지털 PCR의 성능 분리의 기술적 측면에 대해 설명합니다.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Red Top Vacutainer&#160;</td>
			<td>Beckon Dickinson</td>
			<td>366441</td>
			<td>no additive, uncoated interior, 10 ml</td>
		</tr>
		<tr>
			<td>Cryovial Tube</td>
			<td>Simport</td>
			<td>T310-3A</td>
			<td>polypropylene, screw cap tube, any size</td>
		</tr>
		<tr>
			<td>QIAamp DNA Blood Mini Kit</td>
			<td>Qiagen</td>
			<td>51106</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly(A)</td>
			<td>Sigma</td>
			<td>P9403</td>
			<td>disloved in TE buffer (10 mM Tris-Cl pH 8.0 + 1 mM EDTA) to 5 &#181;g/&#181;l&#160;</td>
		</tr>
		<tr>
			<td>Absolute Ethanol (200 Proof)</td>
			<td>Fisher Scientific</td>
			<td>BP2818-500</td>
			<td></td>
		</tr>
		<tr>
			<td>DPBS (with CaCl and MgCl)</td>
			<td>Sigma</td>
			<td>D8662</td>
			<td></td>
		</tr>
		<tr>
			<td>0.2 mL PCR 8-strip Tubes</td>
			<td>MidSci</td>
			<td>AVST</td>
			<td></td>
		</tr>
		<tr>
			<td>8-strip Caps, Dome</td>
			<td>MidSci</td>
			<td>AVSTC-N</td>
			<td></td>
		</tr>
		<tr>
			<td>EZ DNA Methylation-Lightning Kit</td>
			<td>Zymo</td>
			<td>D5031</td>
			<td></td>
		</tr>
		<tr>
			<td>ddPCR Supermix for Probes (No dUTP)</td>
			<td>Biorad</td>
			<td>1863024</td>
			<td></td>
		</tr>
		<tr>
			<td>Buffer Control for Probes</td>
			<td>Biorad</td>
			<td>1863052</td>
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			<td>Human Unmethylated/Methylated Primer/Probe mix</td>
			<td>Life Technologies</td>
			<td>AH21BH1</td>
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			<td>EcoR1</td>
			<td>New England Biolabs</td>
			<td>R0101L</td>
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			<td>twin.tec PCR Plate 96, semi-skirted</td>
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			<td>Pierceable Foil Heat Seal</td>
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			<td>PX1 PCR Plate Sealer</td>
			<td>Biorad</td>
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			<td>QX200 AutoDG Droplet Digital PCR System</td>
			<td>Biorad</td>
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			<td>Automated Droplet Generation Oil for Probes</td>
			<td>Biorad</td>
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			<td>DG32 Cartridge for Automated Droplet Generator</td>
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			<td>Pipet Tips for Automated Droplet Generator</td>
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			<td>186-4120</td>
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			<td>Pipet Tip Bins for Automated Droplet Generator</td>
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			<td>C1000 Touch Thermal Cycler</td>
			<td>Biorad</td>
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			<td>QX200 Droplet Reader</td>
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			<td>ddPCR Droplet Reader Oil</td>
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</table>

measurement of differentially methylated ins dna species in human serum samples as a biomarker of islet &#946; cell death

The death of islet &#946; cells is thought to underlie the pathogenesis of virtually all forms of diabetes and to precede the development of frank hyperglycemia, especially in type 1 diabetes. The development of sensitive and reliable biomarkers of &#946; cell death may allow for early therapeutic intervention to prevent or delay the development of diabetes. Recently, several groups including our own have reported that cell-free, differentially methylated DNA encoding preproinsulin (INS) in the circulation is correlated to &#946; cell death in pre-type 1 diabetes and new-onset type 1 diabetes. Here, we present a step-by-step protocol using digital PCR for the measurement of cell-free INS DNA that is differentially methylated at cytosine at position -69 bp (relative to the transcriptional start site). We demonstrate that the assay can distinguish between methylated and unmethylated cytosine at position -69 bp, is linear across several orders of magnitude, provides absolute quantitation of DNA copy numbers, and can be applied to samples of human serum from individuals with new-onset type 1 diabetes and disease-free controls. The protocol described here can be adapted to any DNA species for which detection of differentially methylated cytosines is desired, whether from circulation or from isolated cells and tissues, and can provide absolute quantitation of DNA fragments.

적절하게 데이터를 해석하기 위해, 우리는 각 디지털 PCR 실행의 메틸화 및 메틸화 대상 INS의 DNA 모두 플라스미드 컨트롤을 사용합니다. 이러한 컨트롤은 메틸화 및 비 메틸화 된 DNA에 대응하는 신호가 명확하게 구별되어 있는지 확인하십시오. 도 1은 바이 설 파이트 변환 메틸화 INS DNA (도 1a)를 포함하는 플라스미드 컨트롤 메틸화 <em...

Watch this Scientific Journal Video about Measurement of Differentially Methylated INS DNA Species in Human Serum Samples as a Biomarker of Islet Î² Cell Death at JoVE.com

Measurement of Differentially Methylated INS DNA Species in Human Serum Samples as a Biomarker of Islet &#946; Cell Death

Islet &#946; cell death precedes development of type 1 diabetes, and detecting this process may allow for early therapeutic intervention. Here, we provide a detailed description of how to measure differentially methylated INS DNA species in human serum as a biomarker of &#946; cell death.

된 유의 메틸화 측정<em&gt; INS</em&gt; 바이오 마커 작은 섬의 β 세포 죽음 등 인간의 혈청 샘플에서 DNA 종

The death of islet &#946; cells is thought to underlie the pathogenesis of virtually all forms of diabetes and to precede the development of frank ...

measurement-differentially-methylated-ins-dna-species-human-serum

Research

JoVE Journal

Genetics

6.4K 조회수.  Indiana University School of Medicine. Islet β cell death precedes development of type 1 diabetes, and detecting this process may allow for early therapeutic intervention. Here, we provide a detailed description of how to measure differentially methylated INS DNA species in human serum as a biomarker of β cell death. 

비디오: Measurement of Differentially Methylated INS DNA Species in Human Serum Samples as a Biomarker of Islet β Cell Death

Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures

Circadian clocks are functional in all light-sensitive organisms, allowing for an adaptation to the external world by anticipating daily environmental changes. Considerable progress in our understanding of the tight connection between the circadian clock and most aspects of physiology has been made in the field over the last decade. However, unraveling the molecular basis that underlies the function of the circadian oscillator in humans stays of highest technical challenge. Here, we provide a detailed description of an experimental approach for long-term (2-5 days) bioluminescence recording and outflow medium collection in cultured human primary cells. For this purpose, we have transduced primary cells with a lentiviral luciferase reporter that is under control of a core clock gene promoter, which allows for the parallel assessment of hormone secretion and circadian bioluminescence. Furthermore, we describe the conditions for disrupting the circadian clock in primary human cells by transfecting siRNA targeting CLOCK. Our results on the circadian regulation of insulin secretion by human pancreatic islets, and myokine secretion by human skeletal muscle cells, are presented here to illustrate the application of this methodology. These settings can be used to study the molecular makeup of human peripheral clocks and to analyze their functional impact on primary cells under physiological or pathophysiological conditions.

Here, we describe settings to monitor in parallel circadian bioluminescence and the secretory activity of human islet cells and primary myotubes. For this, we employed lentiviral gene delivery of a luciferase core clock reporter, followed by in vitro synchronization and collection of outflow medium by continuous cell perifusion.

인간의 기본 세포 배양의 일주기 시계 유전자 발현 및 호르몬 분비의 병렬 측정

Circadian clocks are functional in all light-sensitive organisms, allowing for an adaptation to the external world by anticipating daily environmental ...

연구

유전학

Genome-wide Determination of Mammalian Replication Timing by DNA Content Measurement

Replication of the genome occurs during S phase of the cell cycle in a highly regulated process that ensures the fidelity of DNA duplication. Each genomic region is replicated at a distinct time during S phase through the simultaneous activation of multiple origins of replication. Time of replication (ToR) correlates with many genomic and epigenetic features and is linked to mutation rates and cancer. Comprehending the full genomic view of the replication program, in health and disease is a major future goal and challenge.
This article describes in detail the &#34;Copy Number Ratio of S/G1 for mapping genomic Time of Replication&#34; method (herein called: CNR-ToR), a simple approach to map the genome wide ToR of mammalian cells. The method is based on the copy number differences between S phase cells and G1 phase cells. The CNR-ToR method is performed in 6 steps: 1. Preparation of cells and staining with propidium iodide (PI); 2. Sorting G1 and S phase cells using fluorescence-activated cell sorting (FACS); 3. DNA purification; 4. Sonication; 5. Library preparation and sequencing; and 6. Bioinformatic analysis. The CNR-ToR method is a fast and easy approach that results in detailed replication maps.

We describe here a relatively fast and simple approach for mapping genome-wide mammalian replication timing, from cell isolation to the basic analysis of the sequencing results. A genomic map of a representative replication program will be provided following the protocol.

DNA 콘텐츠 측정에 의한 포유 동물 복제 타이밍의 게놈 전체의 결정

Replication of the genome occurs during S phase of the cell cycle in a highly regulated process that ensures the fidelity of DNA duplication. Each genomic ...

Generation of Fluorescent Protein Fusions in Candida Species

Candida species, prevalent colonizers of the intestinal and genitourinary tracts, are the cause of the majority of invasive fungal infections in humans. Thus, molecular and genetic tools are needed to facilitate the study of their pathogenesis mechanisms. PCR-mediated gene modification is a straightforward and quick approach to generate epitope-tagged proteins to facilitate their detection. In particular, fluorescent protein (FP) fusions are powerful tools that allow visualization and quantitation of both yeast cells and proteins by fluorescence microscopy and immunoblotting, respectively. Plasmids containing FP encoding sequences, along with nutritional marker genes that facilitate the transformation of Candida species, have been generated for the purpose of FP construction and expression in Candida. Herein, we present a strategy for constructing a FP fusion in a Candida species. Plasmids containing the nourseothricin resistance transformation marker gene (NAT1) along with sequences for either green, yellow, or cherry FPs (GFP, YFP, mCherry) are used along with primers that include gene-specific sequences in a polymerase chain reaction (PCR) to generate a FP cassette. This gene-specific cassette has the ability to integrate into the 3'-end of the corresponding gene locus via homologous recombination. Successful in-frame fusion of the FP sequence into the gene locus of interest is verified genetically, followed by analysis of fusion protein expression by microscopy and/or immuno-detection methods. In addition, for the case of highly expressed proteins, successful fusions can be screened for primarily by fluorescence imaging techniques.

Generation of Fluorescent Protein Fusions in Candida Species

PCR-mediated gene modification can be used to generate fluorescent protein fusions in Candida species, which facilitates visualization and quantitation of yeast cells and proteins. Herein, we present a strategy for constructing a fluorescent protein fusion (Eno1-FP) in Candida parapsilosis.

에 형광 단백질 융합의 시대<em&gt; 칸디다</em&gt; 종

Candida species, prevalent colonizers of the intestinal and genitourinary tracts, are the cause of the majority of invasive fungal infections in humans. ...

Assessment of DNA Contamination in RNA Samples Based on Ribosomal DNA

One method extensively used for the quantification of gene expression changes and transcript abundances is reverse-transcription quantitative real-time PCR (RT-qPCR). It provides accurate, sensitive, reliable, and reproducible results. Several factors can affect the sensitivity and specificity of RT-qPCR. Residual genomic DNA (gDNA) contaminating RNA samples is one of them. In gene expression analysis, non-specific amplification due to gDNA contamination will overestimate the abundance of transcript levels and can affect the RT-qPCR results. Generally, gDNA is detected by qRT-PCR using primer pairs annealing to intergenic regions or an intron of the gene of interest. Unfortunately, intron/exon annotations are not yet known for all genes from vertebrate, bacteria, protist, fungi, plant, and invertebrate metazoan species.
Here we present a protocol for detection of gDNA contamination in RNA samples by using ribosomal DNA (rDNA)-based primers. The method is based on the unique features of rDNA: their multigene nature, highly conserved sequences, and high frequency in the genome. Also as a case study, a unique set of primers were designed based on the conserved region of ribosomal DNA (rDNA) in the Poaceae family. The universality of these primer pairs was tested by melt curve analysis and agarose gel electrophoresis. Although our method explains how rDNA-based primers can be applied for the gDNA contamination assay in the Poaceae family,&#160;it could be easily used to other prokaryote and eukaryote species

Here, we present a protocol for tracing genomic DNA (gDNA) contamination in RNA samples. The presented method utilizes primers specific for the internal transcribed spacer region (ITS) of ribosomal DNA (rDNA) genes. The method is suited for reliable and sensitive detection of DNA contamination in most eukaryotes and prokaryotes.

Ribosomal DNA에 따라 RNA 샘플에서 DNA 오염 평가

One method extensively used for the quantification of gene expression changes and transcript abundances is reverse-transcription quantitative real-time ...

Determination of the Optimal Chromosomal Location(s) for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach

The optimal chromosomal position(s) of a given DNA element was/were determined by transposon-mediated random insertion followed by fitness selection. In bacteria, the impact of the genetic context on the function of a genetic element can be difficult to assess. Several mechanisms, including topological effects, transcriptional interference from neighboring genes, and/or replication-associated gene dosage, may affect the function of a given genetic element. Here, we describe a method that permits the random integration of a DNA element into the chromosome of Escherichia coli and select the most favorable locations using a simple growth competition experiment. The method takes advantage of a well-described transposon-based system of random insertion, coupled with a selection of the fittest clone(s) by growth advantage, a procedure that is easily adjustable to experimental needs. The nature of the fittest clone(s) can be determined by whole-genome sequencing on a complex multi-clonal population or by easy gene walking for the rapid identification of selected clones. Here, the non-coding DNA region DARS2, which controls the initiation of chromosome replication in E. coli, was used as an example. The function of DARS2 is known to be affected by replication-associated gene dosage; the closer DARS2 gets to the origin of DNA replication, the more active it becomes. DARS2 was randomly inserted into the chromosome of a DARS2-deleted strain. The resultant clones containing individual insertions were pooled and competed against one another for hundreds of generations. Finally, the fittest clones were characterized and found to contain DARS2 inserted in close proximity to the original DARS2 location.

Determination of the Optimal Chromosomal Locations for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach

Here, the power of a transposon-mediated random insertion of a non-coding DNA element was used to resolve its optimal chromosomal position.

소설 Transposon 중재 방식을 사용 하 여 대장균 의 DNA 요소에 대 한 최적의 염색체 위치 결정

The optimal chromosomal position(s) of a given DNA element was/were determined by transposon-mediated random insertion followed by fitness selection. In ...

Determining Genome-wide Transcript Decay Rates in Proliferating and Quiescent Human Fibroblasts

Quiescence is a temporary, reversible state in which cells have ceased cell division, but retain the capacity to proliferate. Multiple studies, including ours, have demonstrated that quiescence is associated with widespread changes in gene expression. Some of these changes occur through changes in the level or activity of proliferation-associated transcription factors, such as E2F and MYC. We have demonstrated that mRNA decay can also contribute to changes in gene expression between proliferating and quiescent cells. In this protocol, we describe the procedure for establishing proliferating and quiescent cultures of human dermal foreskin fibroblasts. We then describe the procedures for inhibiting new transcription in proliferating and quiescent cells with Actinomycin D (ActD). ActD treatment represents a straightforward and reproducible approach to dissociating new transcription from transcript decay. A disadvantage of ActD treatment is that the time course must be limited to a short time frame because ActD affects cell viability. Transcript levels are monitored over time to determine transcript decay rates. This procedure allows for the identification of genes and isoforms that exhibit differential decay in proliferating versus quiescent fibroblasts.

We describe a protocol for generating proliferating and quiescent primary human dermal fibroblasts, monitoring transcript decay rates, and identifying differentially decaying genes.

확산 및 무부하 인간의 섬유 아 세포의 게놈 넓은 사본 감소율을 결정

Quiescence is a temporary, reversible state in which cells have ceased cell division, but retain the capacity to proliferate. Multiple studies, including ...

Profiling DNA Replication Timing Using Zebrafish as an In Vivo Model System

DNA replication timing is an important cellular characteristic, exhibiting significant relationships with chromatin structure, transcription, and DNA mutation rates. Changes in replication timing occur during development and in cancer, but the role replication timing plays in development and disease is not known. Zebrafish were recently established as an in vivo model system to study replication timing. Here is detailed the protocols for using the zebrafish to determine DNA replication timing. After sorting cells from embryos and adult zebrafish, high-resolution genome-wide DNA replication timing patterns can be constructed by determining changes in DNA copy number through analysis of next generation sequencing data. The zebrafish model system allows for evaluation of the replication timing changes that occur in vivo throughout development, and can also be used to assess changes in individual cell types, disease models, or mutant lines. These methods will enable studies investigating the mechanisms and determinants of replication timing establishment and maintenance during development, the role replication timing plays in mutations and tumorigenesis, and the effects of perturbing replication timing on development and disease.

Profiling DNA Replication Timing Using Zebrafish as an In Vivo Model System

Zebrafish were recently used as an in vivo model system to study DNA replication timing during development. Here is detailed the protocols for using zebrafish embryos to profile replication timing. This protocol can be easily adapted to study replication timing in mutants, individual cell types, disease models, and other species.

DNA 복제 타이밍 Zebrafish Vivo에서 모델 시스템으로 사용 하 여 프로 파일링

DNA replication timing is an important cellular characteristic, exhibiting significant relationships with chromatin structure, transcription, and DNA ...

Endogenous Protein Tagging in Human Induced Pluripotent Stem Cells Using CRISPR/Cas9

A protocol is presented for generating human induced pluripotent stem cells (hiPSCs) that express endogenous proteins fused to in-frame&#160;N- or C-terminal fluorescent tags. The prokaryotic CRISPR/Cas9 system (clustered regularly interspaced short palindromic repeats/CRISPR-associated 9) may be used to introduce large exogenous sequences into genomic loci via homology directed repair (HDR). To achieve the desired knock-in, this protocol employs the ribonucleoprotein (RNP)-based approach where wild type Streptococcus pyogenes Cas9 protein, synthetic 2-part guide RNA (gRNA), and a donor template plasmid are delivered to the cells via electroporation. Putatively edited cells expressing the fluorescently tagged proteins are enriched by fluorescence activated cell sorting (FACS). Clonal lines are then generated and can be analyzed for precise editing outcomes. By introducing the fluorescent tag at the genomic locus of the gene of interest, the resulting subcellular localization and dynamics of the fusion protein can be studied under endogenous regulatory control, a key improvement over conventional overexpression systems. The use of hiPSCs as a model system for gene tagging provides the opportunity to study the tagged proteins in diploid, nontransformed cells. Since hiPSCs can be differentiated into multiple cell types, this approach provides the opportunity to create and study tagged proteins in a variety of isogenic cellular contexts.

Described here is a protocol for tagging endogenously expressed proteins with fluorescent tags in human induced pluripotent stem cells using CRISPR/Cas9. Putatively edited cells are enriched by fluorescence activated cell sorting and clonal cell lines are generated.

인간에서 태그 생 단백질 유도 만능 줄기 세포를 사용 하 여 CRISPR/Cas9

A protocol is presented for generating human induced pluripotent stem cells (hiPSCs) that express endogenous proteins fused to in-frame&#160;N- or ...

Reverse Transcription-Loop-mediated Isothermal Amplification (RT-LAMP) Assay for Zika Virus and Housekeeping Genes in Urine, Serum, and Mosquito Samples

Infection with Zika virus (ZIKV) can be asymptomatic in adults, however, infection during pregnancy can lead to miscarriage and severe neurological birth defects. The goal of this protocol is to quickly detect ZIKV in both human and mosquito samples. The current gold standard for ZIKV detection is quantitative reverse transcription PCR (qRT-PCR); reverse transcription loop-mediated isothermal amplification (RT-LAMP) may allow for a more efficient and low-cost testing without the need for expensive equipment. In this study, RT-LAMP is used for ZIKV detection in various biological samples within 30 min, without first isolating the RNA from the sample. This technique is demonstrated using ZIKV infected patient urine and serum, and infected mosquito samples. 18S ribosomal ribonucleic acid and actin are used as controls in human and mosquito samples, respectively.

Reverse Transcription-Loop-mediated Isothermal Amplification RT-LAMP Assay for Zika Virus and Housekeeping Genes in Urine, Serum, and Mosquito Samples

This protocol provides an efficient and low-cost method to detect Zika virus or control targets in human urine and serum samples or in mosquitoes by reverse transcription loop-mediated isothermal amplification (RT-LAMP). This method does not require RNA isolation and can be done within 30 min.

반대로 Zika 바이러스 및 내부 관리 유전자 소변, 혈 청, 그리고 모기 샘플에 대 한 분석 결과 전사 루프 중재 하는 등온 증폭 (RT-램프)

Infection with Zika virus (ZIKV) can be asymptomatic in adults, however, infection during pregnancy can lead to miscarriage and severe neurological birth ...

The Use of Mouse Mammary Tumor Cells in an In Vitro Invasion Assay as a Measure of Oncogenic Cell Behavior

The in vitro invasion assay uses a protein-rich matrix in a Boyden chamber to measure the ability of cultured cells to pass through the matrix and a porous membrane in a process analogous to the initial steps of cancer cell metastasis. The tested cells can be altered for the gene expression or treated with inhibitors to test for changes in the invasion potential. This experiment tests the aggressive phenotype of the mouse mammary tumor cells to discover and characterize the potential oncogenes that promote cell invasion. This technique, however, can be versatile and adapted to many different applications. The experiment itself can be done in one day and the results are acquired by light microscopy in less than a day. The results include counts of the number of invading cells for comparison and analysis. The in vitro invasion assay is a rapid, inexpensive, and clear-cut method for determining cell behavior in a culture that can be used as an initial assessment before more involved in vivo assays.

The in vitro cell invasion assay is used to measure the potential of cancer metastasis by quantifying the cellular potential for invasion and migration using cell culture inserts containing protein matrix. Cells are challenged to migrate through the protein matrix and a porous membrane, towards a chemoattractant, and then quantified by light microscopy.

종양 발생 세포 행동의 척도로 시험관 내 침략 분석에서 마우스 유방 종양 세포의 사용

The in vitro invasion assay uses a protein-rich matrix in a Boyden chamber to measure the ability of cultured cells to pass through the matrix and a ...

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