MicroRNA Niceleme DNA bağlayıcı Boya Kimya ve Damlacık Dijital PCR kullanarak Sirkülasyon
Summary
A sensitive and accurate method for cell-free microRNAs quantification using a dye-based chemistry and droplet digital PCR technology is described.
Abstract
mikroRNA (miRNA'ların) (hücre içermeyen) dolaşımdaki kan akışı içine hücrelerden salınırlar. dolaşımdaki Belirli mikroRNA miktarı bir hastalık durumu ile bağlantılı hastalık belirteç olarak kullanılmak üzere bir potansiyele sahip olmuştur. Dijital PCR teknolojisi bir boya temelli kimya kullanılarak ve damlacık microRNA ölçümü dolaşan için hassas ve doğru bir yöntem son zamanlarda geliştirilmiştir. Spesifik olarak, nükleik asit (LNA) belirli miRNA'ların mutlak miktarının elde edilmesi mümkün olmaktadır, uyumlu bir damlacık dijital PCR sisteminin yeşil floresan DNA bağlayıcı boya ile miRNA spesifik primerler tabanlı Kilitli kullanılarak. Burada, bu tekniği gerçekleştirmek gibi plazma ve serum gibi biyolojik sıvılarda, içinde miRNA miktarını değerlendirmek için nasıl tarif uygulanabilir ve etkili hem de.
Introduction
MicroRNAs (miRNAs) are released into blood circulation by potentially all the cells of the organism, as a consequence of active release or necrotic and apoptotic processes. Cell-free miRNAs have been detected in the bloodstream either as free stable molecules or linked to lipoproteins or enveloped inside exosomes and microvesicles 1-3. They are believed to function as cell-to-cell communicators 4, and their amount changes in the presence of cancer, cardiac disorders or autoimmune diseases 5-7. Their accurate and reproducible quantification is the basis for their evaluation as disease biomarkers. However, for several reasons already described elsewhere 8,9, miRNA quantification in serum or plasma, as well as other body fluids, could be very challenging 10,11. We recently developed a method for the absolute quantification of circulating miRNAs, based on miRNA-specific LNA primers and DNA-binding dye droplet digital PCR (ddPCR) technology 12. This methodology has been applied to the validation of miRNA breast cancer biomarkers 13,14.
After the partitioning of each reverse-transcribed miRNA molecule inside a nanoliter-sized droplet, it is possible to count the copy number of each miRNA in each sample, basically counting the number of green, and therefore positive, fluorescent droplets. As soon as a PCR reaction occurs, a positive count is achieved, without the need to establish a standard curve or taking PCR efficiency into account in target amount calculation, as it happens with quantitative RT-PCR (RT-qPCR). In addition, ddPCR proved to be more sensitive and accurate than RT-qPCR in circulating miRNA quantification 15. In this article we present the detailed protocol of this methodology, discussing the most relevant steps andspecifically considering serum and plasma clinical samples.
Protocol
Representative Results
Discussion
Sirkülasyon miRNA'lar son derece düşük konsantrasyonlarda, kanda bulunan plazma ve serum örneklerinden elde edilebilir RNA miktarı düşüktür. Bu nedenle, bu tür mikrodizi ve RNA dizi analizi gibi diğer tekniklerle ölçmek zordur. Ayrıca, veriler normalleştirme üzerinde anlaşma genel bir eksikliği ve kan endojen "referans" miRNA'ların varlığı yoktur. Bu bağlamda, serum veya plazma çok düşük dahi olsa ml başına miRNA kopya sayısını sayma yeteneğine sahip damlacık dijital …
Divulgaciones
The authors have nothing to disclose.
Acknowledgements
(-, 2010/15 9980 5 mille n başına. Özel Program Moleküler Klinik Onkoloji) ve Üniversite ve Öğretim İtalyan Bakanlığı MF (MFAG 11676) Kanser Araştırma İtalyan Derneği (AIRC) den ve MN için fon tarafından desteklenen MN Araştırma FIRB 2011 (Proje RBAPIIBYNP).
Materials
| miRNeasy Mini Kit | Qiagen | 217004 | Columns for total RNA, including miRNA, extraction from serum/plasma |
| 100 nmole RNA oligo Cel-miR-39-3p | Integrated DNA Technologies | Custom | Sequence: UCACCGGGUGUAAAUCAGCUUG |
| Universal cDNA synthesis kit II, 8-64 rxns | Exiqon | 203301 | Kit for microRNA reverse transcription |
| MicroRNA LNA PCR primer set | Exiqon | 204000-206xxx and 2100000-21xxxxx | Primers for miRNA amplification inside droplets |
| QX200 droplet generator | BioRad | 186-4002 | Instrument used for droplet reading |
| QX200 droplet reader | BioRad | 186-4003 | Instrument used for droplet generation |
| QuantaSoft software | BioRad | 186-3007 | Software for data collection and analysis |
| PX1 PCR plate sealer | BioRad | 181-4000 | Plate sealer |
| DG8 droplet generator cartridges and gaskets | BioRad | 186-4008 | Cartridges used to mix sample and oil to generate droplets |
| QX200 ddPCR EvaGreen supermix | BioRad | 186-4033/36 | PCR supermix |
| QX200 droplet generator oil for EvaGreen dye | BioRad | 186-4005 | Oil for droplet generation |
Referencias
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