Logical Model Construction Based On Chain Replacement Technology

Computer as one of the most important inventions of the 20th century,has become an indispensable part of human life.Even the development of the computer is obvious to all,the speed and the amount of information stored in computer requirements also more and more high.With the progress of the electronic components gradually close to its physical limits,the traditional computer also faces unprecedented challenges.Looking for new materials to improve even replace traditional silicon based computer become a hot topic of scientists.In 1994,Dr Adleman[1]of the University of Southern California used DNA strands to solve a math classic problem of graph theory in the test tube,for the first time to prove the feasibility of molecular computing in experiments.The structure characteristics of DNA molecule itself determines a variety of advantages of its implementation logic calculation,thus attracted an increasing number of scientists to make a study and research in this field.This paper introduces the background and significance of DNA computing and the current research status at home and abroad.Meanwhile it introduces the basic logic gates of DNA computing(such as AND,OR logic gates,etc.)and some basic biological technology operations(such as agarose gel electrophoresis,etc.).,Basing on the DNA strand displacement technology,the research results and the different testing methods,this paper build two different DNA logic gates.First of all,basing on DNA strand displacement technology,a OR logic gate build which used single-strand DNA ring as reaction substrates,then design three different hybrid areas on the ring that can respectively complement with three part double-stranded input signal,control the fluorescence quenching and release,and build a three input OR logic gate by measuring the release of the fluorescent signal.The generated complex polymer as the substrate reaction,through strand displacement to distinguish different colors of fluorescent signal building an AND logic gate,forming a cascade reaction,completing the logic operation.The model which design DNA ring,and control the release and binding strands achieve the release or quencher of the fluorescence signal,in turn to realize the transmission of information.Secondly through DNA strand displacement technology designed a different from the traditional logic gate model of detection means to improve the sensitivity of the model,the model used short DNA strands to carry on the design,one of the strands modified by biotin at the 5 'end,the corresponding complement links also modified by biotin at the 5' end,by the means of using the specificity of binding force between streptavidin and biotin,streptavidin will be binded on the DNA strands reaction products,so that the rumning speed of reaction products which length is 9 bp significantly is slower than other undecorated double-stranded DNA during electrophoresis.This specific phenomenon is defined as the output signal to complete the logic operation.The model does not need complex detection means,and the biological process is clear,the experimental operation is easy to implement and its cost is low.This title provides basis and reference for building the more complex logic gates based on biological macromolecules.