| Adverse drug reactions do great harm in clinical medicines and pharmaceutical industries, to which individual variation to drug reactions is one of the important causes. The individual variation may be caused by many factors, such as genetics, environment, disease stage and diet, etc, among which genetic polymorphism is a common and uncontrollable factor. Investigation and elucidation of the mechanism for the generation of inter-individual/inter-racial variation to drug reactions is an important subject to improve the drug therapeutic effects and human living quality. The task of pharmacogenomics is to elucidate the role that genetics plays in the variation of individual reactions to drug or xeno materials, especially focused on the elucidation of the mechanism of individual variation by the information of genomic sequence or sequence variation. Pharmacogenomics plays an important role in clinical pharmaceutics and new drug research and development. Genechip (oligonucleotide microarray) technology provides a powerful high throughput data mining and analyzing platform for the research and discovery in the fields of modern biomedicine, and is increasingly widely used in pharmacogenomics.Genechip technology is applied in the genotyping and functional study of drug metabolizing enzymes in the present study. In order to improve the performance of oligonucleotide microarrays assays, some key points in genechip technology was studied and discussed.(1) Optimization and comparison were made among three methods of fluorescent labeling (fluorescent labeled primer, incorporation by Taq polymerase, terminal transfer incorporation by TDT). Under each optimized conditions, there was no significant difference between the fluorescently labeled samples prepared by the three methods concerning the features of amplification and labeling efficiency, signal intensity, background, discrimination power. Evaluated from experimental procedure and cost. Incorporation by Taq polymerase is sensitive to reaction conditions, terminaltransfer incorporation by TDT need additional enzyme and reaction steps. The cost of the above two methods is higher than that of the fluorescent labeled primer, and experimental procedure is more complicated. The 3 methods appeal to different application scope and should be reasonably adopted according to reaction conditions and requirements.(2) Two signal amplification methods were designed and evaluated to increase the fluorescent signal intensity on DNA microarrays, namely multilabeled branched primer and multi-detected point primer, which increase the number of labeled fluorescent molecules per segment at the same time of specific amplification of target segment, therefore to increase the detectable fluorescent molecules per hybridization spot and to improve the detecting sensitivity. It was showrn, with the application of the methods, fluorescent signal intensity was increased by 3-4 times, detecting sensitivity to the minimal sample quantity was lowered by 100 times than that of single labeled primer.(3) A novel genechip preparation chemistry was designed and studied, and was systematically compared with the commonly used preparation methods of the aldehyde coated slides-aminated probes and Br-coated slides-thioated probes, and its application in gene expression profiling and SNP detection was testified. The novel probe, namely bi-functional probe, has thioated bases and free aminal group at one end. Quantitative comparison of the hybridization signals showed that 3' end modified bi-functional probes had higher immobilization efficiency and signal intensity on the aldehyde-coated slides and Br-coated slides than that of the aminated probes or thioated probes, the signal intensity of the bi-functional probes was 30-40% higher than that of aminated probes, and over 3 times that of thioated probes, and there is significant difference between the signal intensities of the 3 probes (P <0.01).(4) A novel SNP detection method was designed with combination of the...
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