Biological parts ,one of the most important tools in the research of synthetic biology ,have been designed ,created and documented in large numbers, most of which ,however, lack scalability. To be more precise, the scalability of a biological part refers to its ability of handling of expanding scale of input and output and the ability of expansion in function. In our project, we aim to demonstrate that a scalable biological part could be devised through proper arrangement of certain sequences in the presence of some protein. We resort to an scalable electronic component ,PLD or Programmable Logic Device in this project. The definition of PLD from Wikipedia is quoted as below:” A programmable logic device or PLD is an electronic component used to build reconfigurable digital circuits. Unlike a logic gate, which has a fixed function, a PLD has an undefined function at the time of manufacture. Before the PLD can be used in a circuit it must be programmed, that is, reconfigured.” That is, digital systems could be integrated to it at will through computer programming by the user, instead of producing an electronic component with a fixed function. Actually, we have constructed a biological part that functions as a PLD, though primitive. The most basic elements in digital circuits are the AND gate and OR gate. We resort to Cre/LoxP system to enable the biological part with the ability to interchange between AND gate and OR gate by regulation of the concentration of the protein Cre.readmore


With the help of site-specific recombination, we manage to change the logic from the physical layer. To a further step, we design a system whose logic changes between AND and OR.readmore


We can transform AND gate into OR gate through a flip of the sequence between opposite loxP sites. Moreover, based on a similar idea, our system shows a strong scalability in further design.readmore