Detection of ricin in beverages using cell-free protein synthesis in a microfluidic device

Abstract

In this work a microchannel array device was used to implement passive pumping through the channels to enhance cell-free protein synthesis yield by delivering nutrients to the protein synthesis reactions. The setup enhanced the sensitivity of ricin detection where the implementation of the device caused the positive control with no ricin to be 33 times greater than samples with ricin in contrast to implementing the reaction in a microcentrifuge tube where the positive control had only twice the amount of protein with ricin present. Furthermore, the use of the device helped reduce the reagent consumption and the cost by a factor of eight and the assay time by a factor of 7 while allowing for high-throughput studies by enabling running 192 parallel experiments. Finally, the setup was used to test the presence of ricin in beverages where the limit of detection ranged from 2pM for orange juice and 170pM for diet soda, an interesting observation highlighted the importance of testing the effect of the beverage on the luminescence signal which could be a direct effect on the enzymatic reaction or an indirect one by affecting the protein synthesis reaction itself.