This work was funded by a National Institutes of Health R01 (DC009453 support to CWB).

NOTA: Antes de fornecer amostras de saliva todos os sujeitos deram consentimento informado em conformidade com as diretrizes para o tratamento de seres humanos do Hospital Nacional Infantil. 1. Saliva coleta e armazenamento <ol><li> Antes da coleta de saliva, garantir que a boca do tema é livre de alimentos ou outras substâncias estranhas, tendo o assunto lavar a boca com água e evitar comer ou beber por 30 minutos antes de coletar a amostra. </li><li> Abrir um tubo de centrífuga de 15 ml com 2,5 ml de tampão de estabilização de DNA 2 certificando-se de evitar tocar no interior da tampa ou do tubo, e o sujeito tem cuspir 2,5 ml de saliva na solução-tampão. Nota: Recolha de mais de 2,5 ml de saliva pode levar à degradação da amostra a partir de uma proporção suficiente de amostra para tampão de estabilização do ADN. Coleta de muito pouca saliva irá reduzir os rendimentos esperados do protocolo. Para avaliar volumes da coleção, use os gradientes numeradas no lado de tele tubo. </li><li> Recoloque a tampa e misturar por inversão até que a mistura é homogeneizada. A agitação vigorosa não é necessário. Armazenar as amostras a temperatura ambiente durante o armazenamento a curto prazo ou a 4 ° C para armazenamento a longo prazo (&gt; 3 meses). </li></ol> 2. Preparativos Iniciais e lise celular <ol><li> Antes de iniciar a extração, aqueça um banho de água a 37 ° C, e preparar um balde de gelo. Três tubos de 15 ml de centrífuga cônicos serão necessários para cada amostra extraída. Os três tubos será utilizado para conter o sedimento de células e de proteínas, a final ADNg extraída, e os sobrenadantes de isopropanol e etanol. </li><li> Recuperar amostras de armazenamento e amostras inverta várias vezes em seguida, vortex em velocidade média por 15 segundos. </li><li> Dispense 2,5 ml da amostra num tubo de centrífuga de 15 ml limpo, e adicionar 5 ml de solução de lise celular. Misturar a amostra 50 vezes por inversão, e incubar à temperatura ambiente durante 30 min. </li></ol> Remoção 3 RNA <ol><li> Adicionar 40 ul de ARNase A Solbuição de 100 mg / ml, e incubar a 37 ° C durante 15 min. </li><li> Retirar a amostra a partir da 37 ° C e banho de água fria no gelo por 3 min. <ol><li> Após a incubação com RNase A, aumentar a temperatura do banho de água a 65 ° C durante o passo de rehidratação ADN do protocolo. </li></ol></li></ol> 4. Protein e remoção de lipídeos <ol><li> Adicionam-se 50 ul de proteinase K a solução de 20 mg / mL, misturar várias vezes por inversão, e incubar à temperatura ambiente durante um mínimo de 30 min. Nota: Este é um possível ponto de pausa para o protocolo. Após a adição da solução de proteinase K, a amostra pode ser armazenada a 4 ° C até que a extracção pode ser concluído. O armazenamento a 4 ° C durante até 24 h não foi demonstrado ter um efeito significativo sobre os rendimentos de extracção ou a qualidade do DNA. Armazenamento de longo prazo nesta fase não foi avaliado. </li><li> Adicionar 1,7 ml de solução de precipitação de proteína, vortex vigorosamente durante 20 segundos a alta velocidade, e colocar em gelo durante 10 min. </li&gt; <li> Uma vez que as amostras foram arrefecidas em gelo durante 10 minutos, centrifuga-se durante 10 min a 3000 xg e 4 ° C. As proteínas precipitadas deve formar um sedimento apertado para continuar. Se a pastilha não é apertado ou a solução está ainda turva, as amostras podem ser arrefecida em gelo durante 5 minutos e mais de centrifugação repetida. As amostras devem ser mantidas em gelo para garantir uma bolinha apertado. </li></ol> 5 Isolamento e purificação de ADNg <ol><li> Num tubo de centrífuga de 15 ml limpo, pipeta de 5 ml de isopropanol e 8 ul de solução do glicogénio puro a 20 mg / ml. </li><li> Verter o sobrenadante contendo o ADNg do passo 4.3 para dentro do tubo que contém a solução de isopropanol e do glicogénio, deixando para trás a proteína precipitada. Uma vez que tenha sido adicionado ao sobrenadante, misturar delicadamente a amostra 50 vezes por inversão e centrifuga-se durante 30 min a 3000 xg e 4 ° C. </li><li> Verter o sobrenadante lentamente para um tubo limpo de 15 ml. Após a remoção do sobrenadante, adicionar 1 ml de etanol a 70% paralavar o sedimento por balanço e lentamente movendo-se delicadamente sobre o etanol o sedimento precipitado várias vezes. Reter o etanol no tubo. </li><li> Após a lavagem inicial, centrifugar a amostra durante 1 min a 2000 xg e 20 ° C. Este passo de centrifugação pode ser feito em cada 4 ° C ou 20 ° C. Não houve efeito significativo da temperatura tem sido demonstrado para esta etapa. </li><li> Após a lavagem e centrifugação inicial da pastilha, verter lentamente a lavagem com etanol a partir do tubo e descarte, em seguida, executar uma segunda lavagem, repetindo os passos 5.3 e 5.4. </li><li> Após a remoção do sobrenadante a partir da segunda lavagem, o sedimento de permitir secar ao ar durante 15 min. <ol><li> Se a amostra não estiver completamente seca, o ar seco durante mais 15 min. </li></ol></li></ol> 6. Reidratação de gDNA <ol><li> Uma vez que a amostra tenha secado, adicionar 300 ul de Tris-EDTA para re-hidratar a pastilha seca ADNg. </li><li> Vortex da amostra durante 5 segundos em velocidade média e coloque em um65 ° C num banho de água quente durante 1 hora. </li><li> Retirar as amostras do banho-maria e incubar O / N à temperatura ambiente. NOTA: Todos os produtos e reagentes utilizados estão listados na tabela de materiais, bem como a Tabela 4. </li></ol>

<ol>
	<li>Quinque, D., Kittler, R., Kayser, M., Stoneking, M., Nasidze, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+saliva+as+a+source+of+human+DNA+for+population+and+association+studies.">Evaluation of saliva as a source of human DNA for population and association studies.</a> Analytical Biochemistry. 353, 272-277 (2006).</li><li>Min, J. 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=High+mircosatellite+and+SNP+genotyping+success+rates+established+in+a+large+number+of+genomic+DNA+samples+extracted+from+mouth+swabs+and+genotypes.">High mircosatellite and SNP genotyping success rates established in a large number of genomic DNA samples extracted from mouth swabs and genotypes.</a> Twin Research and Human Genetics. 9, 501-506 (2006).</li><li>Dlugos, D. J., Scattergood, T. 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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collection+of+blood,+saliva,+and+buccal+cell+samples+in+a+pilot+study+on+the+danish+nurse+cohort:+Comparison+of+the+response+rate+and+quality+of+genomic+DNA.">Collection of blood, saliva, and buccal cell samples in a pilot study on the danish nurse cohort: Comparison of the response rate and quality of genomic DNA.</a> Cancer Epidemiol Biomarkers Prev. 16, 2072-2076 (2007).</li><li>Van Schie, R. C. A. A., Wilson, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Saliva:+A+convenient+source+of+DNA+for+analysis+of+bi-allelic+polymorphisms+of+fc&#947;+receptor+iia+(cd32)+and+fc&#947;+receptor+iiib+(cd16).">Saliva: A convenient source of DNA for analysis of bi-allelic polymorphisms of fc&#947; receptor iia (cd32) and fc&#947; receptor iiib (cd16).</a> Journal of Immunological Methods. 208, 91-101 (1997).</li><li>Dawes, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estimates,+from+salivary+analyses,+of+the+turnover+time+of+oral+mucosal+epithelium+in+humans+and+the+number+of+bacteria+in+an+edentulous+mouth.">Estimates, from salivary analyses, of the turnover time of oral mucosal epithelium in humans and the number of bacteria in an edentulous mouth.</a> Archives of Oral Biology. 48, 329-336 (2003).</li><li>Bahlo, 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=Saliva-derived+DNA+performs+well+in+large-scale,+high-density+single-nucleotide+polymorphism+microarray+studies.">Saliva-derived DNA performs well in large-scale, high-density single-nucleotide polymorphism microarray studies.</a> Cancer Epidemiol Biomarkers Prev. 19, 794-798 (2010).</li><li>Hu, Y., 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=Genotyping+performance+between+saliva+and+blood-derived+genomic+dnas+on+the+dmet+array:+A+comparison.">Genotyping performance between saliva and blood-derived genomic dnas on the dmet array: A comparison.</a> PLoS ONE. 7 (3), e33968 (2012).</li><li>Simmons, T. 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L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ethanol+precipitation+of+DNA.">Ethanol precipitation of DNA.</a> Focus. 7, 1-2 (1985).</li><li>Li, H., Durbin, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fast+and+accurate+short+read+alignment+with+Burrows-Wheeler+Transform.">Fast and accurate short read alignment with Burrows-Wheeler Transform.</a> Bioinformatics. 25, 1754-1760 (2009).</li><li>McKenna, 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=The+Genome+Analysis+Toolkit:+a+MapReduce+framework+for+analyzing+next-generation+DNA+sequencing+data.">The Genome Analysis Toolkit: a MapReduce framework for analyzing next-generation DNA sequencing data.</a> Genome Res. 20, 1297-1303 (2010).</li><li>DePristo, 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+framework+for+variation+discovery+and+genotyping+using+next-generation+DNA+sequencing+data.">A framework for variation discovery and genotyping using next-generation DNA sequencing data.</a> Nature Genetics. 43, 491-498 (2011).</li></ol>

The authors have nothing to disclose.

O presente procedimento é um protocolo de extração de DNA otimizado, que melhorou consideravelmente o rendimento de DNA de alto peso molecular em comparação com os métodos convencionais, sem comprometer a qualidade do DNA. O passo crítico com o maior efeito sobre o rendimento mais foi o passo 5.2, que inclui uma etapa de centrifugação durante a precipitação mais etanol do que qualquer protocolo publicado aqui analisados, com exceção de um que não foi amplamente distribuído 11. Nenhuma alteraç?...

A obtenção de DNA de alta qualidade para estudos genéticos humanos, é essencial no processo de descoberta do gene da doença. Sangue, embora exigindo um procedimento invasivo e também a ser mais caro do que a coleta da saliva, é favorecido para a criação de linhas de células imortalizadas como uma fonte infinita de DNA, ou iPSCs para estudos funcionais e, às vezes DNA do sangue é usado quando as linhas celulares não estão disponíveis. No entanto, a obtenção de sangue requer um flebotomista treinado e sangue tem uma meia-vida mais curta do que a saliva 1. DNA de saliva é mais barata e mais fácil de obter, uma vez que podem ser coletadas e enviadas pelo correio, sem a necessidade de um phlebotomist, aumentando, assim, potenciais piscinas sujeitas bem além da área de abrangência de hospitais e laboratórios 2. Inclusão no estudo pode ser melhorada quando os indivíduos têm a opção de dar uma amostra de saliva em vez de sangue 3, 4. Preocupações sobre a quantidade e qualidade de DNA de saliva pode ter limitado a sua generalizada nose apesar de diversos estudos recentes estudos que comprovem a adequação de toda saliva, com uma média de 4,3 x 10 5 células por mililitro, para testes de DNA ao longo dos mais antigos métodos de cotonetes bucais que não obtiveram uma quantidade significativa de saliva 2, 3, 4, 5, 6. Embora exista uma literatura modesta mostrando a adequação de DNA derivado saliva inteiro para aplicações de genotipagem incluindo métodos baseados em microarrays 8, 9, 10, nenhum estudo examinou sequenciamento de próxima geração (NGS). O objetivo de otimização deste protocolo toda a extração de DNA de saliva era maximizar quantidade e qualidade para aplicações de genética de uma forma rentável que pode ser facilmente implementado em laboratórios com reagentes e consumíveis comuns. Extracção de DNA a partir da saliva requer vários procedimentos: 1) a recolha e armazenamento, 2) lise celular, 3) tratamento com RNase, 4) precipitação de proteínas, 5) precipitação com etanol, 6) de re-hidratação de ADN. A solução de DNA Estabilização tampão, descrito2 anteriormente, funciona adequadamente sem alteração. Nenhuma tentativa foi feita para otimizar o tratamento RNase e etapas de reidratação de DNA. Para cada etapa restante, foram identificadas diversas variáveis ​​que podem afetar o rendimento. Cada variável foi manipulado individualmente e melhoria na produtividade e qualidade foi avaliada estatisticamente. Para as variáveis ​​que foram mostrados para melhorar a produtividade e / ou qualidade do DNA, os valores ótimos foram incluídos no protocolo final.

<table border="0" cellpadding="0" cellspacing="0" width="260">
	<tbody>
		<tr height="49">
			<td height="49" style="height:49px;width:88px;">15ml Centrifuge Tubes</td>
			<td style="width:88px;">Fisher</td>
			<td style="width:84px;">12-565-268</td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:88px;">Cell Lysis Solution</td>
			<td style="width:88px;">Qiagen</td>
			<td style="width:84px;">158908</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:88px;">Proteinase K</td>
			<td style="width:88px;">Sigma</td>
			<td style="width:84px;">P6556</td>
		</tr>
		<tr height="49">
			<td height="49" style="height:49px;width:88px;">Protein Precipitation Solution</td>
			<td style="width:88px;">Qiagen</td>
			<td style="width:84px;">158912</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:88px;">Isopropanol</td>
			<td style="width:88px;">Fisher</td>
			<td style="width:84px;">A416-4</td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:88px;">Glycogen</td>
			<td style="width:88px;">EZ-BioResearch</td>
			<td style="width:84px;">S1003</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:88px;">70% Ethanol</td>
			<td style="width:88px;">Fisher</td>
			<td style="width:84px;">04-355-305</td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:88px;">Tris-EDTA (TE)</td>
			<td style="width:88px;">Fisher</td>
			<td style="width:84px;">BP2473-1</td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:88px;">NaCl</td>
			<td style="width:88px;">Fisher</td>
			<td style="width:84px;">AC194090010</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:88px;">Tris HCl</td>
			<td style="width:88px;">Fisher</td>
			<td style="width:84px;">BP1757-100</td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:88px;">EDTA(0.5M) Solution</td>
			<td style="width:88px;">Fisher</td>
			<td style="width:84px;">03-500-506</td>
		</tr>
		<tr height="49">
			<td height="49" style="height:49px;width:88px;">Sodium Dodecyl Sulfate</td>
			<td style="width:88px;">Fisher</td>
			<td style="width:84px;">BP166-100&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Equipment</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:88px;">Name of Equipment</td>
			<td style="width:88px;">Distributor</td>
			<td style="width:84px;">Catalog#</td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:88px;">Analog Vortex Mixer</td>
			<td style="width:88px;">Fisher</td>
			<td style="width:84px;">02-215-365</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:88px;">Centrifuge 5810R</td>
			<td style="width:88px;">Eppendorf</td>
			<td style="width:84px;">5811 000.010</td>
		</tr>
	</tbody>
</table>

collection and extraction of saliva dna for next generation sequencing

The preferred source of DNA in human genetics research is blood, or cell lines derived from blood, as these sources yield large quantities of high quality DNA. However, DNA extraction from saliva can yield high quality DNA with little to no degradation/fragmentation that is suitable for a variety of DNA assays without the expense of a phlebotomist and can even be acquired through the mail. However, at present, no saliva DNA collection/extraction protocols for next generation sequencing have been presented in the literature. This protocol optimizes parameters of saliva collection/storage and DNA extraction to be of sufficient quality and quantity for DNA assays with the highest standards, including microarray genotyping and next generation sequencing.

Para determinar parâmetros ótimos para Extração de DNA de uma série de extrações de DNA pareadas foi realizada. Uma única amostra de saliva foi dividido e cada porção ensaiada por um dos dois valores possíveis para uma determinada variável. Pelo menos oito repetições de cada teste emparelhado foram realizadas (por exemplo, uma única amostra de saliva foi dividido em alíquotas para testar a extracção com e sem inicial de incubação de 50 ° C). Otimização foi baseada em quatro métricas padr...

Watch this Scientific Journal Video about Collection and Extraction of Saliva DNA for Next Generation Sequencing at JoVE.com

Collection and Extraction of Saliva DNA for Next Generation Sequencing

DNA extraction from saliva can provide a readily available source of high molecular weight DNA, with little to no degradation/fragmentation. This protocol provides optimized parameters for saliva collection/storage and DNA extraction to be of sufficient quality and quantity for downstream DNA assays with high quality requirements.

Coleta e Extração de DNA de saliva para Next Generation Sequencing

The preferred source of DNA in human genetics research is blood, or cell lines derived from blood, as these sources yield large quantities of high quality ...

collection-and-extraction-of-saliva-dna-for-next-generation-sequencing

Research

JoVE Journal

Medicine

38.9K visualizações.  The Research Institute at Nationwide Children's Hospital. DNA extraction from saliva can provide a readily available source of high molecular weight DNA, with little to no degradation/fragmentation. This protocol provides optimized parameters for saliva collection/storage and DNA extraction to be of sufficient quality and quantity for downstream DNA assays with high quality requirements.

Vídeo: Collection and Extraction of Saliva DNA for Next Generation Sequencing

Generation of Alginate Microspheres for Biomedical Applications

Alginate-based materials have received considerable attention for biomedical applications because of their hydrophilic nature, biocompatibility, and physical architecture. Applications include cell encapsulation, drug delivery, stem cell culture, and tissue engineering scaffolds. In fact, clinical trials are currently being performed in which islets are encapsulated in PLO coated alginate microbeads as a treatment of type I diabetes. However, large numbers of islets are required for efficacy due to poor survival following transplantation. The ability to locally stimulate microvascular network formation around the encapsulated cells may increase their viability through improved transport of oxygen, glucose and other vital nutrients. Fibroblast growth factor-1 (FGF-1) is a naturally occurring growth factor that is able to stimulate blood vessel formation and improve oxygen levels in ischemic tissues. The efficacy of FGF-1 is enhanced when it is delivered in a sustained fashion rather than a single large-bolus administration. The local long-term release of growth factors from islet encapsulation systems could stimulate the growth of blood vessels directly towards the transplanted cells, potentially improving functional graft outcomes. In this article, we outline procedures for the preparation of alginate microspheres for use in biomedical applications. In addition, we describe a method we developed for generating multilayered alginate microbeads. Cells can be encapsulated in the inner alginate core, and angiogenic proteins in the outer alginate layer. The release of proteins from this outer layer would stimulate the formation of local microvascular networks directly towards the transplanted islets.

In the following sections, we outline procedures for the preparation of alginate microspheres for use in biomedical applications. We specifically illustrate a technique for creating multilayered alginate microspheres for the dual purpose of cell and protein encapsulation as a potential treatment for type 1 diabetes.

Geração de alginato Microesferas para aplicações biomédicas

Alginate-based materials have received considerable attention for biomedical applications because of their hydrophilic nature, biocompatibility, and ...

Medicina

The &alpha;-test: Rapid Cell-free CD4 Enumeration Using Whole Saliva

There is an urgent need for affordable CD4 enumeration to monitor HIV disease. CD4 enumeration is out of reach in resource-limited regions due to the time and temperature restrictions, technical sophistication, and cost of reagents, in particular monoclonal antibodies to measure CD4 on blood cells, the only currently acceptable method. A commonly used cost-saving and time-saving laboratory strategy is to calculate, rather than measure certain blood values. For example, LDL levels are calculated using the measured levels of total cholesterol, HDL, and triglycerides1. Thus, identification of cell-free correlates that directly regulate the number of CD4+ T cells could provide an accurate method for calculating CD4 counts due to the physiological relevance of the correlates.
The number of stem cells that enter blood and are destined to become circulating CD4+ T cells is determined by the chemokine CXCL12 and its receptor CXCR4 due to their influence on locomotion2. The process of stem cell locomotion into blood is additionally regulated by cell surface human leukocyte elastase (HLECS) and the HLECS-reactive active &alpha;1proteinase inhibitor (&alpha;1PI, &alpha;1antitrypsin, SerpinA1)3. In HIV-1 disease, &alpha;1PI is inactivated due to disease processes 4. In the early asymptomatic categories of HIV-1 disease, active &alpha;1PI was found to be below normal in 100% of untreated HIV-1 patients (median=12 &mu;M, and to achieve normal levels during the symptomatic categories4, 5. This pattern has been attributed to immune inactivation, not to insufficient synthesis, proteolytic inactivation, or oxygenation. We observed that in HIV-1 subjects with &gt;220 CD4 cells/&mu;l, CD4 counts were correlated with serum levels of active &alpha;1PI (r2=0.93, p&lt;0.0001, n=26) and inactive &alpha;1PI (r2=0.91, p&lt;0.0001, n=26) 5. Administration of &alpha;1PI to HIV-1 infected and uninfected subjects resulted in dramatic increases in CD4 counts suggesting &alpha;1PI participates in regulating the number of CD4+ T cells in blood 3.
With stimulation, whole saliva contains sufficient serous exudate (plasma containing proteinaceous material that passes through blood vessel walls into saliva) to allow measurement of active &alpha;1PI and the correlation of this measurement is evidence that it is an accurate method for calculating CD4 counts. Briefly, sialogogues such as chewing gum or citric acid stimulate the exudation of serum into whole mouth saliva. After stimulating serum exudation, the activity of serum &alpha;1PI in saliva is measured by its capacity to inhibit elastase activity. Porcine pancreatic elastase (PPE) is a readily available inexpensive source of elastase. PPE binds to &alpha;1PI forming a one-to-one complex that prevents PPE from cleaving its specific substrates, one of which is the colorimetric peptide, succinyl-L-Ala-L-Ala-L-Ala-p-nitroanilide (SA3NA). Incubating saliva with a saturating concentration of PPE for 10 min at room temperature allows the binding of PPE to all the active &alpha;1PI in saliva. The resulting inhibition of PPE by active &alpha;1PI can be measured by adding the PPE substrate SA3NA. (Figure 1). Although CD4 counts are measured in terms of blood volume (CD4 cells/&mu;l), the concentration of &alpha;1PI in saliva is related to the concentration of serum in saliva, not to volume of saliva since volume can vary considerably during the day and person to person6. However, virtually all the protein in saliva is due to serum content, and the protein content of saliva is measurable7. Thus, active &alpha;1PI in saliva is calculated as a ratio to saliva protein content and is termed the &alpha;1PI Index. Results presented herein demonstrate that the &alpha;1PI Index provides an accurate and precise physiologic method for calculating CD4 counts.

The &amp;#945;-test: Rapid Cell-free CD4 Enumeration Using Whole Saliva

A CD4 enumeration method, the &#x03B1;-test, is described which uses whole saliva to provide rapid and accurate CD4 counts. The &alpha;-test costs pennies and eliminates the need for technical training, costly reagents such as monoclonal antibodies, instrumentation, refrigeration, transport of samples, as well as collection and handling of blood.

O α-teste: Rapid livre de células CD4 enumeração Utilizando saliva total

There is an urgent need for affordable CD4 enumeration to monitor HIV disease. CD4 enumeration is out of reach in resource-limited regions due to the time ...

Collection Protocol for Human Pancreas

This dissection and sampling procedure was developed for the Network for Pancreatic Organ Donors with Diabetes (nPOD) program to standardize preparation of pancreas recovered from cadaveric organ donors. The pancreas is divided into 3 main regions (head, body, tail) followed by serial transverse sections throughout the medial to lateral axis. Alternating sections are used for fixed paraffin and fresh frozen blocks and remnant samples are minced for snap frozen sample preparations, either with or without RNAse inhibitors, for DNA, RNA, or protein isolation. The overall goal of the pancreas dissection procedure is to sample the entire pancreas while maintaining anatomical orientation.
Endocrine cell heterogeneity in terms of islet composition, size, and numbers is reported for human islets compared to rodent islets 1. The majority of human islets from the pancreas head, body and tail regions are composed of insulin-containing &beta;-cells followed by lower proportions of glucagon-containing &alpha;-cells and somatostatin-containing &delta;-cells. Pancreatic polypeptide-containing PP cells and ghrelin-containing epsilon cells are also present but in small numbers. In contrast, the uncinate region contains islets that are primarily composed of pancreatic polypeptide-containing PP cells 2. These regional islet variations arise from developmental differences. The pancreas develops from the ventral and dorsal pancreatic buds in the foregut and after rotation of the stomach and duodenum, the ventral lobe moves and fuses with the dorsal 3. The ventral lobe forms the posterior portion of the head including the uncinate process while the dorsal lobe gives rise to the rest of the organ. Regional pancreatic variation is also reported with the tail region having higher islet density compared to other regions and the dorsal lobe-derived components undergoing selective atrophy in type 1 diabetes4,5.
Additional organs and tissues are often recovered from the organ donors and include pancreatic lymph nodes, spleen and non-pancreatic lymph nodes. These samples are recovered with similar formats as for the pancreas with the addition of isolation of cryopreserved cells. When the proximal duodenum is included with the pancreas, duodenal mucosa may be collected for paraffin and frozen blocks and minced snap frozen preparations.

This video demonstrates a dissection procedure for processing human pancreas into multiple storage formats. Anatomical orientation is maintained throughout the pancreatic regions to allow definition of regional islet composition and density.

Protocolo de Coleta para Pâncreas Humano

This dissection and sampling procedure was developed for the Network for Pancreatic Organ Donors with Diabetes (nPOD) program to standardize preparation ...

Collecting Saliva and Measuring Salivary Cortisol and Alpha-amylase in Frail Community Residing Older Adults via Family Caregivers

Salivary measures have emerged in bio-behavioral research that are easy-to-collect, minimally invasive, and relatively inexpensive biologic markers of stress. This article we present the steps for collection and analysis of two salivary assays in research with frail, community residing older adults-salivary cortisol and salivary alpha amylase. The field of salivary bioscience is rapidly advancing and the purpose of this presentation is to provide an update on the developments for investigators interested in integrating these measures into research on aging. Strategies are presented for instructing family caregivers in collecting saliva in the home, and for conducting laboratory analyses of salivary analytes that have demonstrated feasibility, high compliance, and yield quality specimens. The protocol for sample collection includes: (1) consistent use of collection materials; (2) standardized methods that promote adherence and minimize subject burden; and (3) procedures for controlling certain confounding agents. We also provide strategies for laboratory analyses include: (1) saliva handling and processing; (2) salivary cortisol and salivary alpha amylase assay procedures; and (3) analytic considerations.

We demonstrate: (1) procedures for collection of salivary samples in cognitive impaired older adults by family caregivers in the home setting, (2) procedures for measuring stress activity via salivary cortisol and alpha amylase, and (3) representative profiles. Protocols that allow researchers to study stress-linked processes advance our understanding of biological sensitivity and susceptibility.

Salivary measures have emerged in bio-behavioral research  that are easy-to-collect, minimally invasive, and relatively inexpensive  biologic markers of ...

A Next-generation Tissue Microarray (ngTMA) Protocol for Biomarker Studies

Biomarker research relies on tissue microarrays (TMA). TMAs are produced by repeated transfer of small tissue cores from a &#8216;donor&#8217; block into a &#8216;recipient&#8217; block and then used for a variety of biomarker applications. The construction of conventional TMAs is labor intensive, imprecise, and time-consuming. Here, a protocol using next-generation Tissue Microarrays (ngTMA) is outlined. ngTMA is based on TMA planning and design, digital pathology, and automated tissue microarraying. The protocol is illustrated using an example of 134 metastatic colorectal cancer patients. Histological, statistical and logistical aspects are considered, such as the tissue type, specific histological regions, and cell types for inclusion in the TMA, the number of tissue spots, sample size, statistical analysis, and number of TMA copies. Histological slides for each patient are scanned and uploaded onto a web-based digital platform. There, they are viewed and annotated (marked) using a 0.6-2.0 mm diameter tool, multiple times using various colors to distinguish tissue areas. Donor blocks and 12 &#8216;recipient&#8217; blocks are loaded into the instrument. Digital slides are retrieved and matched to donor block images. Repeated arraying of annotated regions is automatically performed resulting in an ngTMA. In this example, six ngTMAs are planned containing six different tissue types/histological zones. Two copies of the ngTMAs are desired. Three to four slides for each patient are scanned; 3 scan runs are necessary and performed overnight. All slides are annotated; different colors are used to represent the different tissues/zones, namely tumor center, invasion front, tumor/stroma, lymph node metastases, liver metastases, and normal tissue. 17 annotations/case are made; time for annotation is 2-3 min/case. 12 ngTMAs are produced containing 4,556 spots. Arraying time is 15-20 hr. Due to its precision, flexibility and speed, ngTMA is a powerful tool to further improve the quality of TMAs used in clinical and translational research.

A Next-generation Tissue Microarray ngTMA Protocol for Biomarker Studies

The protocol aims at optimizing the construction and quality of tissue microarrays for biomarker research. It includes aspects of planning and design, digital pathology, virtual slide annotation, and automated tissue arraying.

A próxima geração de tissue microarray (ngTMA) Protocolo de Estudos biomarcadores

Biomarker research relies on tissue microarrays (TMA). TMAs are produced by repeated transfer of small tissue cores from a &#8216;donor&#8217; block into ...

Integration of Wet and Dry Bench Processes Optimizes Targeted Next-generation Sequencing of Low-quality and Low-quantity Tumor Biopsies

All next-generation sequencing (NGS) procedures include assays performed at the laboratory bench (&#34;wet bench&#34;) and data analyses conducted using bioinformatics pipelines (&#34;dry bench&#34;). Both elements are essential to produce accurate and reliable results, which are particularly critical for clinical laboratories. Targeted NGS technologies have increasingly found favor in oncology applications to help advance precision medicine objectives, yet the methods often involve disconnected and variable wet and dry bench workflows and uncoordinated reagent sets. In this report, we describe a method for sequencing challenging cancer specimens with a 21-gene panel as an example of a comprehensive targeted NGS system. The system integrates functional DNA quantification and qualification, single-tube multiplexed PCR enrichment, and library purification and normalization using analytically-verified, single-source reagents with a standalone bioinformatics suite. As a result, accurate variant calls from low-quality and low-quantity formalin-fixed, paraffin-embedded (FFPE) and fine-needle aspiration (FNA) tumor biopsies can be achieved. The method can routinely assess cancer-associated variants from an input of 400 amplifiable DNA copies, and is modular in design to accommodate new gene content. Two different types of analytically-defined controls provide quality assurance and help safeguard call accuracy with clinically-relevant samples. A flexible &#34;tag&#34; PCR step embeds platform-specific adaptors and index codes to allow sample barcoding and compatibility with common benchtop NGS instruments. Importantly, the protocol is streamlined and can produce 24 sequence-ready libraries in a single day. Finally, the approach links wet and dry bench processes by incorporating pre-analytical sample quality control results directly into the variant calling algorithms to improve mutation detection accuracy and differentiate false-negative and indeterminate calls. This targeted NGS method uses advances in both wetware and software to achieve high-depth, multiplexed sequencing and sensitive analysis of heterogeneous cancer samples for diagnostic applications.

An integrated system for targeted next-generation sequencing of oncology specimens is described. This cross-platform system is optimized for low-quality and low-quantity tumor biopsies, accommodates low DNA inputs, includes well-characterized multi-variant controls, and features a novel variant caller that is informed by quantitative pre-analytical quality control measures.

Integração de Wet and Processes bancada secos Otimiza alvejado Seqüenciamento Next-geração de baixa qualidade e biópsias de tumores de baixa quantidade

All next-generation sequencing (NGS) procedures include assays performed at the laboratory bench (&#34;wet bench&#34;) and data analyses conducted using ...

Extração econômica de DNA de diatomáceas usando um kit modificado

Extraction of Diatom DNA from Water Samples and Tissues

Diatom testing is an essential auxiliary means in forensic practice to determine whether the corpse drowned in water and to infer the drowning location. Diatom testing is also an important research content in the field of the environment and plankton. The diatom molecular biology testing technology, which focuses on diatom DNA as the primary research object, is a new method of diatom testing. Diatom DNA extraction is the basis of diatom molecular testing. At present, the kits commonly used for diatom DNA extraction are expensive, which increases the cost of carrying out related research. Our laboratory improved the general whole blood genomic DNA rapid extraction kit and obtained a satisfactory diatom DNA extraction effect, thus providing an alternative economical and affordable DNA extraction solution based on glass beads for related research. The diatom DNA extracted using this protocol could satisfy many downstream applications, such as PCR and sequencing.

Autor em destaque: Teste de diatomáceas para exame forense de afogamento 

This article describes a protocol for diatom DNA extraction using a modified common DNA extraction kit.

Extração de DNA de Diatomáceas de Amostras de Água e Tecidos

Diatom testing is an essential auxiliary means in forensic practice to determine whether the corpse drowned in water and to infer the drowning location. ...

Descoberta de biomarcadores não invasivos para proteômica lacrimal usando LC-MS

A Protein Suspension-Trapping Sample Preparation for Tear Proteomics by Liquid Chromatography-Tandem Mass Spectrometry

Tear fluid is one of the easily accessible biofluids that can be collected non-invasively. Tear proteomics has the potential to discover biomarkers for several ocular diseases and conditions. The suspension trapping column has been reported to be an efficient and user-friendly sample preparation workflow for the broad application of downstream proteomic analysis. Yet, this strategy has not been well-studied in the analysis of human tear proteome. The present protocol describes an integrated workflow from clinical human tear samples to purified peptides for non-invasive tear protein biomarker research using mass spectrometry, which provides insights into disease biomarkers and monitoring when combined with bioinformatics analysis. A protein suspension trapping sample preparation was applied and demonstrated the discovery of tear proteome with fast, reproducible, and user-friendly procedures, as a universal, optimized sample preparation for human tear fluid analysis. In particular, the suspension trapping procedure outperformed in-solution sample preparation in terms of peptide recovery, protein identification, and shorter sample preparation time.

Autor em destaque: Avançando na análise do fluido lacrimal usando um protocolo padronizado para pesquisa proteômica 

This protocol describes a method for collecting tear samples using Schirmer strips and an integrated quantitative workflow for discovering non-invasive tear protein biomarkers. The suspension trapping sample preparation workflow enables fast and robust tear sample preparation and mass spectrometric analysis, resulting in higher peptide recovery yields and protein identification than standard in-solution procedures.

Preparação de amostra de suspensão de proteínas para proteômica lacrimal por cromatografia líquida-espectrometria de massas em tandem

Tear fluid is one of the easily accessible biofluids that can be collected non-invasively. Tear proteomics has the potential to discover biomarkers for ...

Methods Article

Coleta e Extração de DNA de saliva para Next Generation Sequencing