Programmable Cell-Free Transcriptional Switches for Antibody Detection

We report here the development of a cell-free in vitro transcription system for the detection of specific targetantibodies. The approach is based on the use of programmableantigen-conjugated DNA-based conformational switches that, upon binding to a target antibody, can trigger the cell-freetranscription of a light-upfluorescence-activating RNA aptamer .The system couples the unique programmability and responsive-ness of DNA-based systems with the specificity and sensitivity offered by in vitro genetic circuitries and commercially available transcription kits. We demonstrate that cell-free transcriptional switches can efficiently measure antibody levels directly in bloodserum. Thanks to the programmable nature of the sensing platform, the method can be adapted to different antibodies: we demonstrate here the sensitive, rapid, and cost-effective detection of three different antibodies and the possible use of this approach for the simultaneous detection of two antibodies in the same solution