Leave a message for inquiry
Leave your phone number, and we'll get in touch with you as soon as possible.
Gene Sequencing
As a core tool in modern life sciences, gene sequencing technology has evolved from laboratory research into clinical diagnostics and personalized medicine, profoundly transforming humanity's understanding of the essence of life and reshaping approaches to disease diagnosis and treatment.
1. The Basic Principles of Gene Sequencing Technology
The core goal of gene-sequencing technology is to determine the precise order of the four DNA bases (A, T, C, G) within a DNA molecule—information that carries an organism’s entire genetic blueprint. Since Frederick Sanger invented the dideoxy chain-termination method (first-generation sequencing) in 1977, gene-sequencing technology has undergone three revolutionary leaps, each of which has exponentially increased sequencing throughput while dramatically reducing costs.
Principle of First-Generation Sequencing (Sanger Method)
As a representative of the first-generation sequencing technology, the dideoxy chain-termination method relies on the use of 2',3'-dideoxynucleotides (ddNTPs) as chain-terminating agents for DNA extension.
Principles of Next-Generation Sequencing (NGS)
The revolutionary breakthrough of next-generation sequencing technology lies in immobilizing DNA fragments onto a solid surface, enabling ultra-high-throughput sequencing through large-scale, parallel reactions.
Principles of Third-Generation Sequencing
The essential feature of third-generation sequencing technology is single-molecule real-time sequencing, which eliminates the need for PCR amplification and allows direct detection of native DNA molecules.
2. Key Performance Metrics of Sequencing Technology
The driving force behind the development of gene-sequencing technology stems primarily from the Human Genome Project and the growing demand for large-scale population genomics studies. As sequencing technologies have moved from major research centers into everyday laboratories and clinical settings, they have given rise to emerging fields such as cancer genomics, microbiome research, and single-cell sequencing.
Key performance indicators of sequencing technology include:
Reading length: Single-round sequencing yields a continuous number of base pairs; long read lengths are advantageous for genome assembly and structural variant detection.
Accuracy: The accuracy rate for base calling typically needs to exceed 99.9% for clinical applications;
Flux: The amount of data generated in a single run determines the project's scale and cost;
Read deeply: The average coverage of genomic regions influences the sensitivity of variant detection. Different application scenarios place varying priorities on these metrics: for instance, tumor mutation screening requires high accuracy and moderate read depth (30–100X), while de novo genome assembly emphasizes long read lengths and high throughput.
As sequencing technologies mature, multi-omics integration and real-time analysis have emerged as new trends. By integrating DNA sequencing with transcriptomic (RNA-seq), epigenomic (ChIP-seq), and proteomic (mass spectrometry) data for comprehensive association analysis, we can gain a holistic understanding of genotype-phenotype relationships. Meanwhile, real-time sequencing technologies like Oxford Nanopore enable immediate data analysis during the sequencing process, showcasing unique advantages in rapid diagnosis of infectious diseases and field-based biological monitoring. Looking ahead, fourth-generation technologies such as quantum sequencing and electron microscopy-based sequencing may further push beyond current limitations, paving the way for faster, more cost-effective genome decoding.
3. The Workflow of DNA Sequencing
Although the underlying principles vary, modern sequencing experiments typically follow a similar standard procedure:
3.1 Sample Preparation : Extract high-quality DNA/RNA from samples such as blood and tissues, performing whole-genome amplification when necessary.
3.2 Library Construction: Fragment the DNA (using sonication or enzymatic digestion), repair the ends, and then ligate sequencing adapters—this process may include size selection and PCR enrichment. For targeted sequencing, hybridization capture or amplicon PCR is also required.
3.3 Cluster Formation/Template Preparation: Second-generation sequencing typically requires in vitro amplification to generate sufficient signal, such as bridge PCR (Illumina) or emulsion PCR (Ion Torrent); third-generation sequencing, however, can directly utilize the original DNA molecules.
3.4 Sequencing Reaction: Depending on the platform's characteristics, the corresponding chemical reactions can take anywhere from a few hours (Ion Torrent) to several days (HiSeq X).
3.5 Data Analysis: The raw image or signal is converted into a base sequence (base calling), followed by quality filtering, alignment to the reference genome, variant detection, and other downstream analyses.
4. Application Areas of Gene Sequencing Technology
Gene sequencing technology, by analyzing the base sequences of DNA or RNA, has permeated every corner of life sciences and medicine—ranging from basic research to clinical applications, and from human health to agricultural breeding. Its broad and profound applications continue to drive revolutionary advancements across these fields.
Typical application areas include medical diagnostics and health management, scientific research and fundamental studies, agriculture and bioengineering, forensic science and individual identification, drug development and personalized medicine, as well as technological advancements and emerging applications.
 |  |
Agricultural Breeding Research | Human Genetic Research |
5. CNI's Typical Gene Sequencing Light Source
Currently, most DNA sequencing methods rely on laser-induced fluorescence technology, using different fluorescent dyes to label the four distinct nucleotides (A, C, G, T). Typically, these methods require either dual-wavelength or quad-wavelength excitation combinations. CNI offers a wide range of wavelength options that precisely match the maximum absorption peaks of each fluorescent marker. Commonly used wavelengths include 320 nm, 335 nm, 349 nm, 355 nm, 365 nm, 375 nm, 405 nm, 430 nm, 450 nm, 473 nm, 488 nm, 515 nm, 532 nm, 561 nm, 577 nm, 589 nm, 633 nm, 639 nm, 670 nm, and 690 nm, with power levels ranging from hundreds of milliwatts to several watts.
Additionally, LED multi-wavelength combination light sources are also commonly used in gene sequencing systems. Typical wavelengths include 365nm, 385nm, 405nm, 440nm, 460nm, 470nm, 480nm, 525nm, 527nm, 555nm, 579nm, 590nm, 630nm, 650nm, 730nm, and white light sources, among others. For detailed specifications, please visit www.cnilaser.com.
Typically, completing a full genome sequencing process usually takes dozens of hours, which places extremely stringent demands on the long-term stability of the laser's wavelength and power output. Generally, an rms stability better than 1% over 100 hours is required, along with exceptional spectral purity—specifically, the laser wavelength cutoff must meet an OD value greater than 5. Additionally, the system is designed to deliver a uniformly illuminated output field with customized spot shapes, achieving a uniformity level exceeding 90%.
 |  |  |
Multi-wavelength gene sequencing light source (Available light sources with any wavelength combination) | Multi-wavelength LED light source 360–730 nm, white light, single- and multi-channel options | Superior to 90% of light fields Homogenization Technology |
Changchun New Industries Optoelectronics Technology Co., Ltd.
Address: No. 888 Jinhu Road, High-Tech Zone, Changchun, 130103, P.R.China
International Tel:+86-431-85603799
Email: sales@cnilaser.com
Send a Message
Leave your phone number, and we'll get in touch with you as soon as possible.