Method and device for detecting target gene or SNP (Single Nucleotide Polymorphism) site of target gene by combining asymmetric PCR (Polymerase Chain Reaction) and magnetic sensitive detector

[0046] Embodiment 1: the detection device of asymmetric PCR combined with magnetic sensitive detector

[0047] 1.1 A detection device for an asymmetric PCR combined with a magnetic sensitive detector according to an embodiment of the present invention, the detection device includes: a DNA extraction and PCR reaction system, a magnetic signal detection chip system, a pump system, a valve system, a heating system and a filter system (see figure 2 ).

[0048] Wherein, the "DNA extraction and PCR reaction system" includes: a sample holding chamber, a PCR reagent holding chamber and a PCR reaction chamber, and the primers in the PCR reagent holding chamber are biotin-labeled primers. The "magnetic signal detection chip system" includes: a magnetic bead holding chamber, a hybridization solution holding chamber and a magnetic bead detection chamber. Wherein, the magnetic sensitive detector in the magnetic bead detection chamber can sense the DNA-modified magnetic beads, and convert t

[0073] Example 2 Detection of SNP signal in CYP2C9-A1075C gene by multiplex asymmetric PCR combined with magnetic sensitive detector

[0074] In this example, the CYP2C9-A1075C and CYP2C19-C806T genes were first amplified by multiple asymmetric PCR, and the SNP signal of the CYP2C9-A1075C gene in blood was detected by molecular hybridization, and then the magnetic signal was detected by a GMR detector.

[0075] Those skilled in the art know that the 1075th nucleotide of human CYP2C9 gene is usually A (ie, normal type), and in some patients, the 1075th nucleotide of this gene will be mutated to C (ie, mutant type). The purpose of this example is to identify the SNP site of the patient's CYP2C9 gene. If the PCR product can only be combined with the capture probe for CYP2C9-1075A (SEQ ID NO: 4), it indicates that the patient only has a normal CYP2C9 gene; if the PCR product can only be combined with the capture probe for CYP2C9-1075C (SEQ ID NO: 5), indicating that the patient has a

[0119] Example 3 Detection of the SNP signal in the CYP2C19-C806T gene by multiplex asymmetric PCR combined with a magnetic detector

[0120] In this example, the CYP2C9-A1075C and CYP2C19-C806T genes were first amplified by multiple asymmetric PCR, the SNP signal of the CYP2C19-C806T gene in blood was detected by molecular hybridization, and then the magnetic signal was detected by a GMR detector.

[0121]Those skilled in the art know that the 806th nucleotide of the human CYP2C19 gene is usually C (ie, normal type), and in some patients, the 806th nucleotide of this gene will be mutated into T (ie, mutant type) 1075. The purpose of this example is to identify the SNP site of the patient's CYP2C19 gene. If the PCR product can only be combined with the capture probe (SEQ ID NO: 9) against CYP2C19-806C, it indicates that the patient only has normal CYP2C19 gene; if the PCR product can only be combined with the capture probe against CYP2C19-806T (SEQ ID NO : 10), indicating that t