DNA-HRM Analysis And Application Based On Optpfluidic Laser

Genes are fundamental factors in determining biological traits.DNA sequence in gene fragments regulates the expression of biological traits through the processes of transcription and translation.Variations in DNA sequence can cause serious consequences.Studies have shown that many heritable diseases are directly related to single-base mutations in DNA sequences,so detecting the base mutations in DNA sequences at the DNA level can detect diseases more faster,more timely,and more accurately.This study mainly uses the Fabry-Perot(FP)cavity as the basis for the detection and analysis of the high-resolution melting(HRM)based on the high-quality factor photo-microfluidic laser cavity.In this paper,three types of DNA are mainly analyzed.(1)99 bases and other two 130 bases long but with different GC contents;(2)four single nucleotide polymorphism(SNP)variant DNAs and three SNP variant DNAs which are related to actual diseases;(3)single-stranded DNA rich in guanine(G)bases.Details as follows:1.DNA-HRM has theoretical analyzed and simulation of based on optical microfluidic laser,analysis of laser-based HRM and fluorescence-based HRM similarities and differences.Subsequently,99 base pairs and two types of 130 base pairs of DNA sequences were studied by experimental analysis.The experimental results showed that the temperature difference is 0.9 to 1? for 99 bases DNA sequence between the target and its mismatched DNA sequence.And is 0.7-0.8? difference for 130 bases long DNA(Type I)and about 0.5? for 130 bases long DNA(Type II)is about.Also,the laser-based HRM transition temperature is reduced by more than 10 °C,compared to the fluorescence-based HRM transition temperature by adjusting the parameters of the exiting laser.In addition,because of the unique nature of the laser,the relationship between the laser emission intensity and the external pumping intensity can be scanned while maintaining the temperature.Target DNA and mismatched DNA can be quickly distinguish according to the results of the slope.This is not possible to come true when using the fluorescence-based HRM.2.Because of the small difference in thermodynamics between before and after SNP mutations,SNP variant DNA was analyzed using a fixed temperature scanning method.First,the four SNP variants of the freely designed design are analyzed.The scanning method at a fixed temperature can distinguish the changes between them.Then,the three most common SNP variant diseases in human heritable diseases: methylenetetrahydrofolate(MTHFR),V factor(Factor V),and globin gene(?-globin)are also analyzed.The different DNA can distinguished by a fixed temperature scan at low temperatures.3.Based on the FP cavity,a single-stranded DNA rich in guanine base is formed to form a G-quadruplex under the induction of external metal cations and an intracavitary fluorescence resonance energy transfer(FRET)phenomenon occurred.The change in receptor signal intensity based on laser-based FRET is more pronounced as compared to fluorescence-based FRET.