Project description:In recent years, tagmentation-based library preparation using a hyperactive version of the Tn5 transposase gained more and more popularity. The limited hands-on time, robustness and high efficiency of the method are essential for the processing of next-generation sequencing libraries form little input material like single cells or the processing of hundreds of samples simultaneously. The hyperactive Tn5 is commercially available (Nextera XT DNA library preparation kit), however, high-throughput experiments with hundreds of samples are costly. Here, we present a highly reproducible Tn5 transposase purification strategy via an N-terminal His6-Sumo3 tag and the workflow for the tagmentation-based NGS library preparation. We demonstrate that NGS libraries processed with the in-house produced Tn5 are of the same quality like those processed with the Nextera XT DNA library preparation kit and that the purification of the transposase is reproducible across institutes. Producing the Tn5 transposase in-house allows for customized experimental design and reduces costs of large-scale experiments dramatically. We describe a novel single cell polyadenylation site mapping protocol that benefits from the fact that the in-house produced Tn5 can be loaded with any desired linker oligonucleotide for tagmentation.
Project description:In recent years, tagmentation-based library preparation using a hyperactive version of the Tn5 transposase gained more and more popularity. The limited hands-on time, robustness and high efficiency of the method are essential for the processing of next-generation sequencing libraries from little input material like single cells or the processing of hundreds of samples simultaneously. The hyperactive Tn5 is commercially available (Nextera XT DNA library preparation kit), however, high-throughput experiments with hundreds of samples are costly. Here, we present a highly reproducible Tn5 transposase purification strategy via an N-terminal His6-Sumo3 tag and the workflow for the tagmentation-based NGS library preparation. We demonstrate that NGS libraries processed with the in-house produced Tn5 are of the same quality like those processed with the Nextera XT DNA library preparation kit and that the purification of the transposase is reproducible across institutes. Producing the Tn5 transposase in-house allows for customized experimental design and reduces costs of large-scale experiments dramatically. We describe a novel single cell polyadenylation site mapping protocol that benefits from the fact that the in-house produced Tn5 can be loaded with any desired linker oligonucleotide for tagmentation.
Project description:Massively parallel DNA sequencing of thousands of samples in a single machine-run is now possible, but the preparation of the individual sequencing libraries is expensive and time-consuming. Tagmentation-based library construction, using the Tn5 transposase, is efficient for generating sequencing libraries but currently relies on undisclosed reagents, which severely limits development of novel applications and the execution of large scale projects. Here, we present simple and robust procedures for Tn5 transposase production and optimized reaction conditions for tagmentation-based sequencing library construction. We further show how molecular crowding agents both modulate library lengths and enable efficient tagmentation from sub-picogram amounts of cDNA. Comparison of single-cell RNA-sequencing libraries generated using produced and commercial Tn5 demonstrated equal performances in terms of gene detection and library characteristics. Finally, as naked Tn5 can be annealed to any oligonucleotide of choice, for example molecular barcodes in single-cell assays or methylated oligonucleotides for bisulfite sequencing, custom Tn5 production and tagmentation enables innovation in sequencing-based applications.
Project description:Deep sequencing of single cell-derived genomic DNA and/or cDNAs brings novel insights into oncogenesis and embryogenesis. However, traditional library preparation for RNA-Seq requires multiple steps, including shearing the target DNA/RNA and following sequential enzymatic reactions, which result in consequent sample loss and stochastic variation at each step. Such variation may significantly affect the output from sequencing. We have found that a new technique of library preparation using hyperactive Tn5 transposase for the next-generation sequencer of Illumina's platform provided high-quality libraries from 100ng of short-length (average 700~800 bp) single-cell level cDNA. This new method reduced the number of steps in the protocol, which resulted in improved reproducibility and reduced variation among the specimens. Two methods of library preparation (sonication, tagmentation with hyperactive Tn5 transposase) were compared in the case of RNA-Seq for single-cell level cDNA. Technical triplicates were used.
Project description:Chromatin immunoprecipitation followed by next generation sequencing (ChIP-seq) is widely used to map histone marks and transcription factor binding throughout the genome. Here we present ChIPmentation, a method that combines ChIP with sequencing library preparation by Tn5 transposase (“tagmentation”). ChIPmentation introduces sequencing-compatible adapters in a single-step reaction directly on bead-bound chromatin, which reduces time, cost, and input requirements, making ChIPmentation a convenient and high-throughput alternative to existing ChIP-seq protocols.
Project description:We describe the Bridge linker-Alul-Tn5 Hi-C (BAT Hi-C) method, which is a simple and efficient method for delineating chromatin conformational features of mouse embryonic stem (mES) cells and uncover DNA loops. This protocol combines Alul fragmentation and biotinylated linker-mediated proximity ligation to obtain kilobase (kb) resolution with a marked increase in the amount of unique read pairs. The protocol also includes chromatin isolation to reduce background noise and Tn5 tagmentation to cut down on preparation time.
Project description:Tn5-mediated transposition of double-strand DNA has been widely utilized in various high-throughput sequencing applications. Here, we report that the Tn5 transposase is also capable of direct tagmentation of RNA/DNA hybrids in vitro. As a proof-of-concept application, we utilized this activity to replace the traditional library construction procedure of RNA sequencing, which contains many laborious and time-consuming processes. Results of Transposase assisted RNA/DNA hybrids Co-tagmEntation (termed “TRACE-seq”) are comparable to traditional RNA-seq methods in terms of detected gene number, gene body coverage, gene expression measurement, library complexity, and differential expression analysis; at the meantime, TRACE-seq enables a one-tube library construction protocol and hence is more rapid (within 6h) and convenient. We expect this tagmentation activity on RNA/DNA hybrids to have broad potentials on RNA biology and chromatin research.
Project description:Background: Next-generation sequencing (NGS) is fundamental to the current biological and biomedical research. Construction of sequencing library is a key step of NGS. Therefore, various library construction methods have been explored. However, the current methods are still limited by some shortcomings. Results: This study developed a new NGS library construction method, Single strand Adaptor Library Preparation (SALP), by using a novel single strand adaptor (SSA). SSA is a double-stranded oligonucleotide with a 3ʹ overhang of 3 random nucleotides, which can be efficiently ligated to the 3′ end of single strand DNA by T4 DNA ligase. SALP can be started with any denatured DNA fragments such as those sheared by Tn5 tagmentation, enzyme digestion and sonication. When started with Tn5-tagmented chromatin, SALP can overcome a key limitation of ATAC-seq and become a high-throughput NGS library construction method, SALP-seq, which can be used to comparatively characterize the chromatin openness state of multiple cells unbiasly. In this way, this study successfully characterized the comparative chromatin openness states of four different cell lines, including GM12878, HepG2, HeLa and 293T, with SALP-seq. Similarly, this study also successfully characterized the chromatin openness states of HepG2 cells with SALP-seq by using 105 to 500 cells. Conclusions: This study developed a new NGS library construction method, SALP, by using a novel kind of single strand adaptor (SSA), which should has wide applications in the future due to its unique performance.