Experimental Studies Of Multichannel Biosensor Chip For Detection Of PML/RARα Fusion Gene In Acute Promyelocytic Leukemia

Acute promyelocytic leukemia (APL) accounts for approximately 10% to 15% of all cases of acute myeloid leukemia (AML). APL patients are of distinct cytomophology, cytogenetics and molecular biology. 95% of APL patients are of distinctive chromosome translocation of t(15;17). The chromosome translocation involves PML gene of chromosome 15 and RARαgene of chromosome 17, which results in the formation of PML/RARαfusion gene finally. PML/RARαfusion gene is APL specific signal of the molecular biology. The detection of PML/RARαfusion gene not only assists the diagnosis of APL, but also has the important significance to quantitate the fusion gene. The traditional morphology and routine PCR technology can't quantitate. Thus the study of new detection technology is the current hot spot in the domanial of PML diagnosis. DNA electrochemical biosensor is a novel biosensor which developed rapidly in recent years. As it has advantages of simplicity, sensitivity, low price, it is one of the important methods for analysis and detection of nucleic acid structure. DNA electrochemical biosensor, which has attracted more and more attention. But every time it only implements the detection of single electrode and is of no good reproducibility. Multichannel biosensor chip is composed of sixteen sensors, and each sensor is composed of three electrode. That is, similar to the three electrodes of the traditional DNA electrochemical biosensor. Thus, according to the autospecific features, combining to the multichannel automatic shifter and electrochemical workstation, gene was detected on the 16-sensor-chip. Every tunnel is a transducer, so the essence of transducer is applied to the development of the chip. The detection on the chip can increase the detection efficiency, decrease the workload and improve the comparability, so the chip technology is also the development of the biosensor chip. Among the total, the application of the multichannel biosensor chip technology is of fast, high efficient, high flux and simultaneous treatment, which is of wide prospect.In order to study the detection of APL PML/RARαfusion gene on the multichannel biosensor chip, first, the whole access of multichannel biosensor chip would be established and the electrochemical behavior on the chip would be investigated. Simultaneously, this article has studied the technology of 16-sensor-chip. Considering the chip is easy to consume, and similar to the three electrodes of the traditional DNA electrochemical biosensor, so correlated study was carried out on the electrode. That is, prophase empirical study of DNA immobilization and detection method was in order to develop 16-sensor-chip combined DNA electrochemical biosensor. This experiment used covalent linkage combined hybridization indicator method, polymer film combined hybridization indicator method, and self-assembly monolayer (SAM)/Au-orientated system combined enzymic method. Experimental result indicated that the above methods could increase immobilized quantities of modified DNA probe, thus it improves the sensitivity and selectivity. Compared the above methods, self-assembly monolayer (SAM)/Au-orientated system combined enzymic method is not only convenient but also minor destruction to chip. So enzymic method was used to the detection of electrical signal on the 16-sensor-chip.In the expirical study of using 16-sensor-chip for the detection of PML/RARαfusion gene, first of all, consistency study of 16-sensor-chip was carried out. Then self-assembly monolayer (SAM)/Au-orientated system combined enzymic method was adopted, and the contrasting experiment was studied when PML/RARαfusion gene was added in and out. Simultaneously, specificity and linearity of PML/RARαfusion gene were detected on the 16-sensor-chip, which provided a good basis of futher detection research in practical samples of PML/RARαfusion gene and other genes.