Clinical Applications of Genetic Sequencers

Genetic sequencer, also known as DNA sequencer, is an instrument used to determine the sequence, type, and quantity of nucleotides in a DNA fragment. It is mainly used in human genome sequencing, genetic diagnosis of human hereditary diseases, infectious diseases, and cancer, forensic paternity testing and individual identification, screening of biological engineering drugs, and hybrid breeding of plants and animals.

There are two types of gene sequencers based on electrophoresis: slab gel electrophoresis and capillary electrophoresis

Slab gel electrophoresis

The gel of slab gel electrophoresis is cast between two glass plates, the thickness of which is generally less than 0.4mm, or even thinner after polymerization. Therefore, it is also called ultra-thin layer gel electrophoresis. It is a classic electrophoresis technique with the advantage of longer sequence reads and the ability to perform multiple samples sequencing on one gel.

Capillary electrophoresis

The high-polymer gel is cast in a capillary tube (inner diameter 50-100μm) to achieve rapid separation of DNA fragments under high voltage and low concentration of gel. It is a fast, efficient, low injection volume, and high sensitivity technique, which can achieve sequencing of up to 750bp.

The application of gene sequencers includes:

Application in the diagnosis of infectious diseases

The sequencing technology can accurately analyze the nucleotide sequence and directly identify, classify, and trace various pathogens through sequence alignment. Clarifying the gene sequence of the corresponding pathogen of a particular infectious disease can provide targeted medication and prevention, improve the effectiveness and safety of medication, and help to discover new pathogens for better prevention.

Application in the diagnosis of hereditary diseases

Diseases caused by gene mutations have the characteristics of heredity and lifelongness. Once a person has this disease, it will cause suffering to themselves and the whole family. By sequencing the genes of the tested individuals, checking the gene mutation status, and determining whether there are genetic hereditary diseases or predicting the probability of offspring illness, gene sequencing can provide guidance for marriage and reduce the incidence of hereditary diseases.

Application in cancer diagnosis

The occurrence of tumors is the result of the interaction between genetic genes and environmental factors, among which genetic genes are inherent and related to whether the human body has a predisposed gene for cancer. The detection of cancer susceptibility genes can detect whether there are genetic predisposition genes or familial clustering carcinogens in the human body, and provide personalized guidance according to individual situations.

Application in drug susceptibility genes

The difference in individual genotypes may result in different medication results for the same drug. Determining the corresponding genotype of patients can achieve more precise medication and maximize the effectiveness of medication.

Application in non-invasive prenatal screening

Fetal genes can be extracted from maternal blood, and prenatal screening of the fetus can be performed through a gene sequencer to know the health status of the fetus in advance, such as screening for Down syndrome.