Research Organization for Nano & Life Innovation, Waseda University, 513 Wasedatsurumaki-cho, Shinjuku-ku, Tokyo, 162-0041, Japan.
PRESTO, Japan Science and Technology Agency (JST), 5-3 Yonban-cho, Chiyoda-ku, Tokyo, 102-0075, Japan.
Sci Rep. 2017 Jul 12;7(1):5199. doi: 10.1038/s41598-017-05436-4.
Massively parallel single-cell genome sequencing is required to further understand genetic diversities in complex biological systems. Whole genome amplification (WGA) is the first step for single-cell sequencing, but its throughput and accuracy are insufficient in conventional reaction platforms. Here, we introduce single droplet multiple displacement amplification (sd-MDA), a method that enables massively parallel amplification of single cell genomes while maintaining sequence accuracy and specificity. Tens of thousands of single cells are compartmentalized in millions of picoliter droplets and then subjected to lysis and WGA by passive droplet fusion in microfluidic channels. Because single cells are isolated in compartments, their genomes are amplified to saturation without contamination. This enables the high-throughput acquisition of contamination-free and cell specific sequence reads from single cells (21,000 single-cells/h), resulting in enhancement of the sequence data quality compared to conventional methods. This method allowed WGA of both single bacterial cells and human cancer cells. The obtained sequencing coverage rivals those of conventional techniques with superior sequence quality. In addition, we also demonstrate de novo assembly of uncultured soil bacteria and obtain draft genomes from single cell sequencing. This sd-MDA is promising for flexible and scalable use in single-cell sequencing.
大规模平行单细胞基因组测序对于进一步理解复杂生物系统中的遗传多样性至关重要。全基因组扩增(WGA)是单细胞测序的第一步,但在传统反应平台中,其通量和准确性都不足。在这里,我们介绍了一种新的方法——单液滴多次置换扩增(sd-MDA),该方法可以在保持序列准确性和特异性的同时,实现单细胞基因组的大规模平行扩增。数以万计的单细胞被分隔在数百万个皮升级别的液滴中,然后通过微流控通道中的被动液滴融合进行裂解和 WGA。由于单细胞在隔室中被隔离,它们的基因组在没有污染的情况下被扩增到饱和状态。这使得能够从单细胞中高通量获取无污染和细胞特异性的序列读数(21,000 个单细胞/小时),与传统方法相比,提高了序列数据的质量。该方法可扩增单个细菌细胞和人类癌细胞的 WGA。所获得的测序覆盖率与传统技术相当,但序列质量更优。此外,我们还展示了未培养土壤细菌的从头组装,并从单细胞测序中获得了草图基因组。这种 sd-MDA 有望在单细胞测序中灵活且可扩展地使用。