TX-TL Basics

TX-TL (short for transcription-translation) is a technology for prototyping biological circuits using cell extracts. The video below shows the core processes of transcription and translation, which are implemented in the TX-TL cell-free system.

Learn more about TX-TL:

• Website: Biomolecular Breadboards site on OpenWetWare
• Research paper: Protocols for Implementing an Escherichia coli Based TX-TL Cell-Free Expression System for Synthetic Biology , Zachary Z. Sun, Clarmyra A. Hayes, Jonghyeon Shin, Filippo Caschera, Richard M. Murray, Vincent Noireaux. Journal of Visualized Experiments (JoVE), (79):e50762, 2013.

Using Genetic Components to Affect Circuit Behavior

By mixing fragments of DNA into TX-TL, we can make use of biological processes to express genes and implement logical functions such as repression and activation.

Learn more about biomolecular systems:

• Website: Synthetic biology article on Wikipedia
• Textbook: Biomolecular Feedback Systems, Domitilla Del Veccho and Richard M. Murray. Princeton University Press, 2014. [free PDF download available]

Logic Gate (AND) Example

As an example, we can use multiple fragments of DNA to implement a logical "AND" gate. This gate (or switch) will turn on the expression of a protein only if two input signals are both present.

Design My Own Switch