scholarly journals Miniaturization and optimization of 384-well compatible metagenomic sequencing library preparation

2018 ◽  
Author(s):  
Madeline Y Mayday ◽  
Lillian M Khan ◽  
Eric D Chow ◽  
Matt S Zinter ◽  
Joseph L DeRisi

AbstractPreparation of high-quality sequencing libraries is a costly and time-consuming component of metagenomic next generation sequencing (mNGS). While the overall cost of sequencing has dropped significantly over recent years, the reagents needed to prepare sequencing samples are likely to become the dominant expense in the process. Furthermore, libraries prepared by hand are subject to human variability and needless waste due to limitations of manual pipetting volumes. Reduction of reaction volumes, combined with sub-microliter automated dispensing of reagents without consumable pipette tips, has the potential to provide significant advantages. Here, we describe the integration of several instruments, including the Labcyte Echo 525 acoustic liquid handler and the iSeq and NovaSeq Illumina sequencing platforms, to miniaturize and automate mNGS library preparation, significantly reducing the cost and the time required to prepare samples. Through the use of External RNA Controls Consortium (ERCC) spike-in RNAs, we demonstrated the fidelity of the miniaturized preparation to be equivalent to full volume reactions. Furthermore, detection of viral and microbial species from cell culture and patient samples was also maintained in the miniaturized libraries. For 384-well mNGS library preparations, we achieved a savings of over 80% in materials and reagents alone, and reduced preparation time by 90% compared to manual approaches, without compromising quality or representation within the library.

2016 ◽  
Author(s):  
Jo Ann Tan ◽  
Alexander S Mikheyev

The high cost of library preparation remains a major obstacle to sequencing large numbers of individual genomes. Illumina’s proprietary tagmentation technology allows for rapid and easy preparation of sequencing libraries, but remains prohibitively expensive for many users. Here we propose a modified version of the protocol, which uses Illumina reagents at 1/20th the scale. We show that the scaled-down protocol performs comparably to that of the manufacturer on a non-model insect genome. Surprisingly, the scaled-down protocol also produced 14% fewer PCR duplicates that the full-scale protocol. Since PCR duplicates effectively wasted redundant data, our protocol presented here can help save not just library preparation costs, but sequencing costs as well.


2015 ◽  
Vol 370 (1660) ◽  
pp. 20130622 ◽  
Author(s):  
Kelly M. Harkins ◽  
Jane E. Buikstra ◽  
Tessa Campbell ◽  
Kirsten I. Bos ◽  
Eric D. Johnson ◽  
...  

The field of ancient DNA (aDNA) has rapidly accelerated in recent years as a result of new methods in next-generation sequencing, library preparation and targeted enrichment. Such research is restricted, however, by the highly variable DNA preservation within different tissues, especially when isolating ancient pathogens from human remains. Identifying positive candidate samples via quantitative PCR (qPCR) for downstream procedures can reduce reagent costs, increase capture efficiency and maximize the number of sequencing reads of the target. This study uses four qPCR assays designed to target regions within the Mycobacterium tuberculosis complex (MTBC) to examine 133 human skeletal samples from a wide geographical and temporal range, identified by the presence of skeletal lesions typical of chronic disseminated tuberculosis. Given the inherent challenges working with ancient mycobacteria, strict criteria must be used and primer/probe design continually re-evaluated as new data from bacteria become available. Seven samples tested positive for multiple MTBC loci, supporting them as strong candidates for downstream analyses. Using strict and conservative criteria, qPCR remains a fast and effective screening tool when compared with screening by more expensive sequencing and enrichment technologies.


2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Vera Rykalina ◽  
Alexey Shadrin ◽  
Hans Lehrach ◽  
Tatiana Borodina

Abstract Here, we describe an electrophoresis free assay for characterizing Tn5 transposomes fragmentation efficiency in a tagmentation reaction, in which double-stranded DNA is fragmented and tagged with adapter sequences. The assay uses plasmid DNA as a reference tagmentation substrate. Fragmentation efficiency is analyzed by comparative qPCR which measures the difference (ΔCt) in amplification of a specific plasmid region before and after tagmentation: more efficient fragmentation is characterized by a larger number of cleavage events within the amplified region, a delayed increase in the amplification curve and as a result, a larger ΔCt. Tagmentation reactions characterized with the same ΔCt exhibit the same fragment size distribution on an agarose gel. The ΔCt values measured can be used to quantitatively determine the relative performance of Tn5 transposome assemblies in optimization experiments and to standardize between batch variations in transposomes for use in next-generation sequencing library preparation. Moreover, the use of a reference tagmentation template added during next-generation sequencing library preparation enabled monitoring of the input DNA fragmentation. The presented qPCR-based assay is quick, contamination-safe, high-throughput and cost-efficient.


BMC Genomics ◽  
2012 ◽  
Vol 13 (1) ◽  
pp. 1 ◽  
Author(s):  
Samuel O Oyola ◽  
Thomas D Otto ◽  
Yong Gu ◽  
Gareth Maslen ◽  
Magnus Manske ◽  
...  

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