The Research On Several Theoretic Problems Of DNA Computer

DNA computing is a new calculation method that used biological molecule DNA as calculation medium and biochemical reaction as calculation tool. Generally considering, although the ability of the classical digital computer is unassailable when it executes serial task, DNA computing shows natural advantage compared with the classical digital computer in solving the problems that all possible solution should be verified which exist everywhere. In the dissertation, several problems in DNA molecule synthesis and DNA computing coding of DNA computer manufacture are studied and discussed mainly from the point of sticker models and sticker systems. The detailed contents are as follows: The coding problem is the core problem of DNA computer realization. Firstly because it has an impact on the quality of DNA sequence synthesis; Secondly because the quality of coding directly influences the process whether the hybridization can be proceeded according to the desired target; Thirdly because the quality of coding has effects not only on the space size of solution but also on whether the problem of "exponential explosion of space size of solution"which relates closely to the development of DNA computer can be solved. So we lucubrate the coding problem of DNA computer in-depth based on the discussion of major influencing factors of coding problem. The problem of DNA molecule synthesis is not only the all-important problem which should be disposed firstly in the biological operation process, but also the problem which must be solved in DNA computer manufacture. The realization of DNA computer should be automatic completely. The problem of how to find the solution to link up the synthesizing and coding process of DNA molecule and other biochemical operation automatically is becoming the sixty-four-dollar question of completely automatic DNA computer research. In order to solve this problem, we must focus our mind on the basic principle and techniques of DNA molecule synthesis firstly. The basic combination principle model of cooperation DNA computer and functions of each unit inside the system are proposed and discussed detailedly based on the theory, completeness, universality of DNA computing, sticker model and sticker system. The organizations of classical digital computer are referenced. A new method of molecule logic gate realization based on the sticker model of DNA computing is presented in this paper. Logic gate, input and output signals are all composed of DNA strands. AND operation of logic gate can be achieved by this method. In theory, the molecular logic gate based on DNA is considered as the fundamental of both DNA computer architecture and hardware technology. Logic gate, inputs and outputs are all DNA strands in this method. This technique employs standard operations of biomedical engineering, such as polymerase chain reaction (PCR), agarose gel electrophoresis, labeling and detecting of probe. These techniques may be applied on DNA chips to develop DNA computer.