NGS library construction is the first step in the Next-Generation Sequencing (NGS) technical process, and it is also a crucial link. It involves the process of converting DNA or RNA molecules in a sample through a series of processing steps into a library that can be sequenced by a high-throughput sequencer. This article will provide a detailed explanation of NGS database construction:

1. Definition of NGS database construction

NGS library construction refers to the process of extracting DNA or RNA from biological samples (such as blood, tissue, etc.) and converting it into a library suitable for high-throughput sequencer reading through a series of biochemical means. This library contains a large number of DNA or RNA fragments, each with a specific sequence tag so that it can be identified and distinguished during sequencing.

2. Steps to build NGS database

NGS library construction usually includes the following key steps:

1. Sample preparation: First, DNA or RNA needs to be extracted from biological samples. This step usually includes sample collection, processing and purification to ensure that the quality and quantity of extracted nucleic acids meet the requirements of subsequent experiments.

2. DNA/RNA extraction: Use appropriate extraction methods (such as chemical methods, physical methods, etc.) to isolate DNA or RNA from the sample. The key to this step is to ensure the integrity and purity of the nucleic acid.

3. Library construction:

1>Fragmentation: Cut DNA or RNA samples into short fragments. This can be achieved through methods such as chemical shearing, enzyme digestion or ultrasonic shearing. The fragment length is usually between 100-1000bp, depending on the purpose of library construction and the requirements of the sequencer.

2>End repair and ligation: Repair the ends of DNA or RNA fragments, and add appropriate linkers (a short DNA sequence) to ligate the DNA fragments into the library. This step is to ensure that the DNA fragments can exist stably during subsequent amplification and sequencing processes.

3> Amplification and purification: Amplify the number of DNA fragments in the library through methods such as PCR, and remove impurities and unconnected DNA fragments through purification steps to improve the quality and purity of the library.

4. Library quality control: Carry out quality control on the constructed library to ensure that it meets the sequencing requirements. Commonly used library quality control methods include polyacrylamide gel electrophoresis, colorimetric methods, and fluorescence quantification.

3. Application of NGS database construction

NGS library construction technology is widely used in research in the fields of genomics, transcriptomics, and epigenomics. By constructing libraries and performing high-throughput sequencing of DNA or RNA in samples, a large amount of genome, transcriptome and epigenome information can be obtained, helping us to deeply understand the mysteries of life and the mechanisms of disease.

For example, in tumor-related research, NGS database construction technology can help doctors quickly and accurately understand the details of DNA mutations in patients' tumor cells, thereby assisting treatment and guiding medication. In the field of reproductive genetics, NGS database construction technology can screen and diagnose fetal genetic diseases through non-invasive prenatal diagnosis technology.

4. Summary

NGS library construction is one of the key steps of NGS technology. It provides the possibility to achieve large-scale, high-throughput genome sequencing and transcriptome sequencing by converting DNA or RNA samples into libraries suitable for high-throughput sequencer reading. . With the continuous development and improvement of NGS technology, NGS database construction technology will play an important role in research in more fields.