Journal of Chromatography & Separation Techniques
Open Access

Electrophoresis for the Detection of Genetic Mutations and Variants

Hong Farwa^{* *}Correspondence: Hong Farwa, Department of Chromatography, University of Peking, Beijing, China, Email:

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Description

Genetic mutations and variants play important roles in human health, disease susceptibility, and biological diversity. Detecting these mutations and variations accurately and efficiently is essential for diagnosing genetic disorders, studying population genetics, and advancing personalized medicine. Electrophoresis, a technique that separates molecules based on their charge and size under an electric field, has been a cornerstone in molecular biology for detecting genetic variations. This manuscript provides a comprehensive description of how electrophoresis is used in the detection of genetic mutations and variants, the principles behind the technique, and the specific applications in genetics and medical diagnostics. Electrophoresis operates by applying an electric field to a sample placed within a gel or capillary matrix. Different molecules migrate at varying rates depending on their charge-to-mass ratio, size, and the properties of the matrix. When applied to Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA) analysis, electrophoresis enables the separation of nucleic acids by their length, allowing for the visualization and quantification of genetic mutations and variants. Common types of electrophoresis techniques used in genetic studies include gel electrophoresis, capillary electrophoresis, and pulse-field gel electrophoresis. Gel electrophoresis, one of the most widely used forms of electrophoresis, separates DNA fragments by size within an agarose or polyacrylamide gel matrix. DNA is negatively charged due to its phosphate backbone and migrates towards the positive electrode when an electric field is applied. Smaller fragments migrate faster than larger ones, creating distinct bands that can be visualized through staining or fluorescence. Gel electrophoresis is particularly effective for detecting insertion or deletion mutations and for analyzing Restriction Fragment Length Polymorphisms (RFLPs), which are variations in DNA fragment lengths resulting from enzyme cuts at mutation sites. Capillary Electrophoresis (CE) is an advanced electrophoresis technique that separates DNA fragments in a narrow capillary tube filled with an electrolyte solution. The high voltage applied in CE results in rapid separation of DNA molecules, providing a highly sensitive and automated method for analyzing genetic mutations. CE is frequently used for Single Nucleotide Polymorphism (SNP) detection, Short Tandem Repeat (STR) profiling, and DNA sequencing. The precision and automation of CE make it a valuable tool in clinical diagnostics and forensic analysis. Pulsed-Field Gel Electrophoresis (PFGE) is a specialized technique used for separating large DNA molecules, often exceeding 20 kilobases in length. PFGE applies an alternating electric field at various angles to the gel, enabling the resolution of large DNA fragments that standard electrophoresis techniques cannot achieve. This method is widely used in microbial genetics and epidemiology, allowing researchers to detect structural variations, large-scale insertions or deletions, and rearrangements in genomes.

One of the primary applications of electrophoresis in genetics is the detection of mutations, which can be important for diagnosing hereditary diseases. Gel electrophoresis, often coupled with restriction enzymes that target specific DNA sequences, can reveal length variations in these genes, enabling mutation screening. Capillary electrophoresis also plays a significant role in genotyping, where it facilitates the identification of Single Nucleotide Polymorphisms (SNPs) and other genetic markers essential for personalized medicine and pharmacogenetics. Electrophoresis is particularly effective in detecting insertions and deletions (indels) by observing differences in fragment lengths. Indels can disrupt gene function and lead to diseases, such as cystic fibrosis or Duchenne muscular dystrophy. SNPs are the most common form of genetic variation, representing single base-pair changes within the genome. Capillary electrophoresis, often combined with fluorescent tagging, enables high-throughput SNP detection, essential for genetic mapping, disease susceptibility studies, and personalized medicine. SNP analysis through CE has been instrumental in Genome-Wide Association Studies (GWAS), where thousands of SNPs across the genome are analyzed to identify associations with complex traits and diseases. STRs are short DNA sequences that repeat multiple times in a row, with variations in the number of repeats among individuals. STR profiling is commonly used in forensic science for human identification, paternity testing, and genetic diversity studies. Capillary electrophoresis is the method of choice for STR analysis due to its high resolution and ability to precisely measure the length of DNA fragments. Each individual’s unique STR pattern acts as a genetic fingerprint, allowing forensic experts to match DNA samples with high accuracy. Comparative Genomic Hybridization (CGH) is a technique that detects DNA copy number variations between different genomes, which can indicate duplications or deletions linked to cancer and other diseases. In array-CGH, labeled DNA samples are hybridized to a microarray containing thousands of known sequences, and differences in fluorescence intensity reveal copy number variations. Capillary electrophoresis is often used to verify CGH results, especially when targeting specific genomic regions associated with genetic disorders. Electrophoresis is also widely used in microbiology for pathogen detection and strain typing.

Conclusion

Electrophoresis has proven to be an indispensable tool in the detection and analysis of genetic mutations and variants. From detecting small nucleotide changes to large structural variations, electrophoresis provides a reliable, sensitive, and versatile approach for analyzing genetic material. Techniques such as gel electrophoresis, capillary electrophoresis, and pulsed-field gel electrophoresis have each contributed uniquely to genetic research, diagnostics, and forensic analysis. Advances in automation and sensitivity have further extended the applications of electrophoresis, enabling high-throughput analyses in clinical settings and large-scale genetic studies. As research continues to expand into more complex genetic mutations and interactions, the development of electrophoresis methods remains essential. By improving detection capabilities and integrating with complementary technologies like mass spectrometry and next-generation sequencing, electrophoresis will continue to play a vital role in advancing genetic diagnostics and personalized medicine. Its accessibility and adaptability ensure that electrophoresis remains at the forefront of molecular biology, supporting the ongoing quest to understand genetic variability and its impact on human health.