Project description:Cell free DNA (cfDNA) in human plasma carries abundant information on physiological condition, especially in cancer patients such as esophageal cancer. Next-generation sequencing (NGS) as a rapidly developed technology could decode the information effectively. As a key step of NGS, using existing methods to construct cfDNA sequencing libraries is limited by several shortcomings. In this study, we developed a new NGS library construction method for highly degraded DNA, cfDNA as example, based on Single strand Adaptor Library Preparation (SALP). With the high ligation efficiency of single strand adaptor (SSA) which overhangs 3 random bases at 3' end of a double-strand DNA, the new method could construct the sequencing library with high sensitivity without using specific enzymes except T4 DNA ligase and Taq polymerase. With the special designed barcode T adaptor (BTA), multiple libraries constructed from different samples can be amplified in unbiased strategy and facility to compare. Using this method, this study successfully sequenced and compared totally 20 cfDNA samples derived from esophageal cancer patients and healthy people in whole genome scale. This study also compared the chromatin state between cancer patients and healthy people using cfDNA, identified the significant difference between different health condition. Our findings extend the application of cfDNA beyond the analysis with degraded DNA fragments itself, to the transcription regulation level, which also provide an important clue for biopsy of esophageal cancer and other diseases.
Project description:Deep sequencing of strand-specific cDNA libraries is now a ubiquitous tool for identifying and quantifying RNAs in diverse sample types. The accuracy of conclusions drawn from these analyses depends on precise and quantitative conversion of the RNA sample into a DNA library suitable for sequencing. Here, we describe an optimized method of preparing strand-specific RNA deep sequencing libraries from small RNAs, variably sized RNA fragments obtained from ribonucleoprotein particle footprinting experiments or fragmentation of long RNAs. Our approach works across a wide range of input amounts (400 pg to 200 ng), is easy to follow and produces a library in 2–3 days at relatively low reagent cost, all while giving the user complete control over every step. Because all enzymatic reactions were optimized and driven to apparent completion, sequence diversity and species abundance in the input sample are well preserved. Deep sequencing libraries from either a randomized RNA oligo or an equimolar miRNA mix were analyzed for evenness of capture.
Project description:Deep sequencing of strand-specific cDNA libraries is now a ubiquitous tool for identifying and quantifying RNAs in diverse sample types. The accuracy of conclusions drawn from these analyses depends on precise and quantitative conversion of the RNA sample into a DNA library suitable for sequencing. Here, we describe an optimized method of preparing strand-specific RNA deep sequencing libraries from small RNAs, variably sized RNA fragments obtained from ribonucleoprotein particle footprinting experiments or fragmentation of long RNAs. Our approach works across a wide range of input amounts (400 pg to 200 ng), is easy to follow and produces a library in 2–3 days at relatively low reagent cost, all while giving the user complete control over every step. Because all enzymatic reactions were optimized and driven to apparent completion, sequence diversity and species abundance in the input sample are well preserved.
Project description:Sub-genomewide shRNAs constructed using an optimized selection algorithm and microRNA backbone provide stronger evidence for follow-up studies
Project description:We report the application of an uscfDNA-oriented sequencing pipeline profiling the cell-free DNA populations in plasma. The uscfDNA sequencing pipeline include two uscfDNA-optimized extraction methods (QiaM and SPRI) and one control extraction method (QiaC). Final libraries are made with a single-stranded library prepartion kit. We generate genome-wide maps revealing the presence of an uscfDNA population (25-99bp) in addition to the mncfDNA (100-250bp).
Project description:We report the application of an uscfDNA-oriented sequencing pipeline profiling the cell-free DNA populations in plasma. The uscfDNA sequencing pipeline include two uscfDNA-optimized extraction methods (QiaM and SPRI) and one control extraction method (QiaC). Final libraries are made with a single-stranded library prepartion kit. We generate genome-wide maps revealing the presence of an uscfDNA population (25-99bp) in addition to the mncfDNA (100-250bp).
Project description:We report the application of an uscfDNA-oriented sequencing pipeline profiling the cell-free DNA populations in plasma. The uscfDNA sequencing pipeline include two uscfDNA-optimized extraction methods (QiaM and SPRI) and one control extraction method (QiaC). Final libraries are made with a single-stranded library prepartion kit. We generate genome-wide maps revealing the presence of an uscfDNA population (25-99bp) in addition to the mncfDNA (100-250bp).