Study On Fabrication Of Typeography Instrument For Dna Array Synthesis And Related Technologies

Biochip technology is a great breakthrough of life science after recombinant DNA technology and polymerase chain reaction. Gene chip is the most mature technology of biochip technology and has been widely studied in these years. Spotting and in situ synthesis were the major methods for establishing DNA chips. The disadvantages of spotting are higher manufacturing costs when the population of the features of a bio-chip is big and relatively low density of integration; while in situ synthesis possesses a greater number of probe and higher accuracy than the spotting one, and its disadvantages are difficult to fabricate, limitation in the synthesis of a long sequence, and requirement of patented reagents. In the future, the development direction of gene chip will be the large-scale and batch production by using automation technology. Therefore, the development of simple, cheap and high efficient synthesis methods for fabricating DNA microarrays is extremely important.On the basis of that the novel method of establishing gene chips by typography technique, our research was focused on the related technology of gene chip by typography technique, and the thesis consists of the following contents:(1) A preliminary study was done on the auto-machine for in situ synthesis of gene chip by typography technique. Statistics of deviations for the templates made of two materials in the machine was investigated in order to improve accuracy of the auto-machine. The results prove that the templates made of stainless steel are better than ones made of polytetrafluoroethylene.(2) Genomic DNA was extracted and the fourth exon of p53 gene was amplified by PCR. We extracted genomic DNA from normal and cervical cancer patients by the phenol and chloroform approaches and designed the primers for PCR to amplify the fourth exon of p53 gene. The electrophoresis patterns of genomic DNA were clear by improving the phenol and chloroform approaches. And the fourth exon of p53 was amplified by PCR.(3) A systematic study was carried out on the preparation of gold nanoparticles and application of gold label silver staining. Colloidal gold was prepared by sodium citrate reduction, sodium citrate tannin reduction, ascorbic acid reduction and sodium borohydride reduction, respectively, and corresponding size, morphology, dispersion, and stability of the samples were characterized and compared. The results shown that sodium citrate tannin reduction method was prone to prepare the colloidal gold with a diameter of ca.13 nm. This approach processed many merits such as narrow size distribution, uniform morphology, good stability and dispersion. It could be used to labelling probes directly. And the technique of gold label silver staining was used in detection of hybridization signal. Its sensitivity was very high. The gold label silver staining is a sensitive method for detection of gene chip.