Peripheral blood is a valuable, non-invasive source of biomarkers which include circulating miRNAs. Using microfluidic array-based techniques, miRNAs can be successfully measured in small amounts of blood plasma (< 0.5 mL) using cDNA pre-amplification. However, the use of heparin-based anticoagulants for blood collection hinders the detection of circulating miRNAs due to its inhibitory effect on PCR components. Although pre-treatment with heparinase have been shown to overcome heparin contamination in blood, its effect has not been described in array-based analyses or more sensitive applications with smaller sample volumes (i.e. 200 μL plasma) requiring pre-amplification. We show that the treatment of miRNA extracted from heparinised plasma with an optimised concentration of Bacteroides heparinase I prior to cDNA pre-amplification dramatically improves the number of detectable miRNA from 2 to 67 targets on the TaqMan^® Array Human MicroRNA Cards. Furthermore, the titrated amount of heparinase (3 U) gave the best miRNA detection compared to those used in previous studies (6–24 U). This study provides novel data which demonstrates that heparinase treatment is compatible with protocols that involve pre-amplification of cDNA and microfluidic array-based techniques. This an improved methodology that permits miRNA-based biomarker analysis from small volume of heparinised plasma.

外周血是包括循环miRNA在内的生物标志物的宝贵，非侵入性来源。使用基于微流体阵列的技术，可以使用cDNA预扩增在少量血浆（<0.5 mL）中成功测量miRNA。但是，由于使用肝素类抗凝剂对PCR成分具有抑制作用，因此阻碍了循环miRNA的检测。尽管已显示使用肝素酶进行的预处理可以克服血液中的肝素污染，但在基于阵列的分析或需要预扩增的较小样品量（即200μL血浆）的更敏感应用中，尚未描述其作用。我们显示了从肝素化血浆中提取的miRNA的最佳浓度的拟杆菌的治疗。肝素酶I之前的cDNA预扩增显着地提高检测的miRNA的从上的TaqMan 2至67的目标数^®阵列人微RNA卡。此外，与以前的研究（6-24 U）相比，滴定量的肝素酶（3 U）可提供最佳的miRNA检测。这项研究提供了新的数据，表明肝素酶治疗与涉及cDNA的预扩增和基于微流控阵列的技术的协议兼容。这是一种改进的方法，可从少量肝素化血浆中进行基于miRNA的生物标记分析。