Abstract: The present invention falls within the field of biotechnology, and specifically discloses a method for constructing a cyclized library and a ring-forming linker. The method comprises: 1) breaking a DNA sequence into fragments; 2) enabling two ends of the broken fragment to form 3? end protrusions; and 3) cyclizing the fragment with 3? end protrusions to form a ring-shaped library by means of a ring-forming linker, wherein the ring-forming linker is a double chain which is not completely paired and has 3? end protrusion at both ends, and the 3? end protrusion of the ring-forming linker is complementary to the 3? end protrusion of the broken fragment. According to the present invention, an A-sticky end of the end is formed by means of repairing the end of and the adding A to the broken DNA fragment, and same is then complementary to the specifically designed linker T sticky end to form a cyclized structure, and the connection at the gap is completed under the action of a ligase.

Abstract: Provided are a mask, a sample collecting tube, and a pathogen collecting apparatus. The mask includes a mask body, a breather valve fixed on the mask body, and a sampling structure including a pathogen adsorption portion. The pathogen adsorption portion is disposed on an inner side of the breather valve and is adapted to adsorb pathogens in exhaled gas. The pathogen adsorption portion is adapted to enter the sample collecting tube to be in contact with a sample preservation solution in the sample collecting tube.

Abstract: Provided are a vesicular adaptor and a single-chain cyclic library constructed by using the adaptor. The library can be used for RNA sequencing and other sequencing platforms dependent on a single-stranded cyclic library, and has the advantage of high throughput sequencing, high accuracy and simple operations.

Abstract: Improved single molecule sequencing methods, compositions, and devices, are provided. In a first aspect, the present invention provides a multi-pass method of sequencing a target sequence using nanopore sequencing, the method comprising: i) providing a non-naturally occurring concatemer nucleic acid molecule comprising a plurality of copies of the target sequence; ii) nanopore sequencing at least three copies of the target sequence in the concatemer, thereby obtaining a multi-pass sequence dataset, wherein the multi-pass sequence dataset comprises target sequence datasets for the at least three copies of the target sequence; and iii) using the multi-pass sequence dataset to determine the target sequence.

Abstract: Provided are a vesicular adaptor and a single-chain cyclic library constructed by using the adaptor. The library can be used for RNA sequencing and other sequencing platforms dependent on a single-stranded cyclic library, and has the advantage of high throughput sequencing, high accuracy and simple operations.

Abstract: The present invention provides a primer for nucleic acid random fragmentation and a nucleic acid random fragmentation method. The primer consists of a plurality of upstream random primers and downstream random primers. The sequence composition of the upstream random primers is 5?-X-Y-3?, and the sequence composition of the downstream random primers is 5?-P-Y?-X?-close-3?, wherein Y and Y? are random sequences, X is all or part of sequences of a sequencing platform 5? end adaptor, X? is all or part of sequences of a sequencing platform 3? end adaptor, P is phosphorylation modification, and close is close modification. The primer of the present invention adopts double random anchoring of both the upstream random primers and the downstream random primers, and a DNA sample can be randomly broken.

Abstract: Provided are a vesicular linker and a single-chain cyclic library constructed by using the linker. The library can be used for RNA sequencing and other sequencing platforms dependent on a single-stranded cyclic library, and has the advantages of high throughput sequencing, high accuracy and simple operations.

Abstract: Provided is a linker element and a method of using the linker element to construct a sequencing library, wherein the linker element consists of a linker A and a linker B, the linker A is obtained through the complementary pairing of a long nucleic acid strand and a short nucleic acid strand, the 5? end of the long strand has a phosphoric acid modification, and the 3? end of the short strand has an enclosed modification, with enzyme sites in the short strand; and the linker B is a nucleic acid single strand, and the 3? end thereof can be in a complementary pairing with the 5? end of the long strand of the linker A. Using the linker element of the present invention for constructing a sequencing library ensures the linking directionality of the linkers while solving the problems of fragment interlinking, linker self-linking and low linking efficiency, and reducing the purification reaction between steps, shortening the linking time and reducing costs.

Abstract: Provided are a target region enrichment method based on multiplex PCR, and a reagent, the method comprising: connecting a first linker and a second linker respectively at two ends of a nucleic acid segment containing target regions to be enriched so as to obtain a linker-connected product; performing a PCR amplification on the linker-connected product using a first primer specifically bound to the first linker and a second primer specifically bound to the second linker to obtain an amplified product, the first primer or the second primer having a first affinity label; capturing a single strand having the first affinity label in the amplified product using a solid phase carrier; performing single primer linear amplification using a third primer with the captured single strand as a template; performing exponential amplification using the third primer and the first primer, with the linearly amplified product as the template, to obtain a product containing the target regions.

Abstract: Provided are a method for constructing a nucleic acid single-stranded cyclic library and the reagents used therein. By the combination of interruption via a transposase with a restricted nick translation reaction, the method realizes a simple and rapid nucleic acid single-stranded cyclic library construction.

Abstract: Disclosed are a nucleic acid fragmentation method and a sequence combination. The method comprises the following steps: subjecting a denatured nucleic acid to annealing and an extension reaction by using a single-stranded 5?-end extension primer, wherein the single-stranded 5?-end extension primer comprises a sequencing platform adaptor sequence of a 5? end and a connected random sequence, and the random sequence is subjected to annealing on a random site of the denatured nucleic acid; and directionally connecting a double-stranded 3?-end adaptor sequence to the 3? end of the nucleic acid generated in the extension reaction, and carrying out denaturalization and purification to obtain a fragmented single-stranded nucleic acid with adaptor sequences on two ends.

Abstract: Provided is a method of constructing a sequencing library using an adaptor element in a bubble shape. The bubble-shaped adaptor is ligated to a DNA fragment respectively at the 3?-terminal and the 5?-terminal i.e., two bubble-shaped adaptors with same sequences are ligated in one step. The bubble-shaped adaptor-ligated product is then amplified with a primer complementary to the 3?-terminal of the long-chain nucleic acid of the bubble-shaped adaptor, so as to replace the non-paired sequence in the short-chain nucleic acid.

Abstract: Provided are a method for constructing a nucleic acid single-stranded cyclic library and the reagents used therein. By the combination of interruption via a transposase with a restricted nick translation reaction, the method realizes a simple and rapid nucleic acid single-stranded cyclic library construction.

Abstract: Improved single molecule sequencing methods, compositions, and devices, are provided. In a first aspect, the present invention provides a multi-pass method of sequencing a target sequence using nanopore sequencing, the method comprising: i) providing a non-naturally occurring concatemer nucleic acid molecule comprising a plurality of copies of the target sequence; ii) nanopore sequencing at least three copies of the target sequence in the concatemer, thereby obtaining a multi-pass sequence dataset, wherein the multi-pass sequence dataset comprises target sequence datasets for the at least three copies of the target sequence; and iii) using the multi-pass sequence dataset to determine the target sequence.

Abstract: Disclosed are a nucleic acid fragmentation method and a sequence combination. The method comprises the following steps: subjecting a denatured nucleic acid to annealing and an extension reaction by using a single-stranded 5?-end extension primer, wherein the single-stranded 5?-end extension primer comprises a sequencing platform adaptor sequence of a 5? end and a connected random sequence, and the random sequence is subjected to annealing on a random site of the denatured nucleic acid; and directionally connecting a double-stranded 3?-end adaptor sequence to the 3? end of the nucleic acid generated in the extension reaction, and carrying out denaturalization and purification to obtain a fragmented single-stranded nucleic acid with adaptor sequences on two ends.

Abstract: Provided in the present invention are a method for constructing a nucleic acid single-stranded cyclic library and reagent kit thereof. The method comprises the steps of using a transposase embedding complex to randomly break nucleic acids and connect a first linker; connecting a second linker at a gap; performing a first PCR reaction, wherein the 5? end of one of the primers has a first affinity tag, resulting in a product with two ends connected to different linker sequences; binding the product to a solid vector having a second affinity tag; degenerating and separating single strands having no affinity tag; and cyclizing the single strands.

Abstract: Provided are a target region enrichment method based on multiplex PCR, and a reagent, the method comprising: connecting a first linker and a second linker respectively at two ends of a nucleic acid segment containing target regions to be enriched so as to obtain a linker-connected product; performing a PCR amplification on the linker-connected product using a first primer specifically bound to the first linker and a second primer specifically bound to the second linker to obtain an amplified product, the first primer or the second primer having a first affinity label; capturing a single strand having the first affinity label in the amplified product using a solid phase carrier; performing single primer linear amplification using a third primer with the captured single strand as a template; performing exponential amplification using the third primer and the first primer, with the linearly amplified product as the template, to obtain a product containing the target regions.

Abstract: Disclosed are a one-stop treatment method for breaking a nucleic acid by means of a transposase, and a reagent. The method of the present invention comprises the following steps: conducting random breaking of a nucleic acid by using a transposase-embedded complex, the transposase-embedded complex comprising a transposase and a first adaptor comprising a transposase identification sequence; adding a first reagent to conduct treatment, so as to break an absorption effect of the transposase to a target sequence of the nucleic acid; adding a second reagent to conduct treatment, so as to weaken the influence of the first reagent on a follow-up enzyme-catalyzed reaction; and conducting a PCR reaction by using a product generated after the second reagent treatment as a template component, so as to obtain a PCR product of a broken nucleic acid segment whose two ends are connected to adaptors.

Abstract: Provided in the present invention are a method for constructing a nucleic acid single-stranded cyclic library and reagents thereof. The method comprises the steps of using a transposase embedding complex to randomly break nucleic acids and connect a first linker; connecting a second linker at a gap; performing a first PCR reaction, wherein the 5? end of one of the primers has a first affinity tag, resulting in a product with two ends connected to different linker sequences; binding the product to a solid vector having a second affinity tag; degenerating and separating single strands having no affinity tag; and cyclizing the single strands.