ViTest - A rapid field-based diagnostic tool to detect grapevine diseases

ViTest is a fast point-of-care nucleic acid test to differentiate between two grapevine diseases: Flavescence Dorée and Bois Noir. Flavescence Dorée is infectious and needs to be quarantined quickly while Bois Noir is not. 

We start by extracting DNA from infected plant material using a microneedle patch. We then amplify the sequences corresponding to grapevine (endogenous control) and the diseases (if they are present). This step is performed using Recombinase Polymerase Amplification, an isothermal nucleic acid amplification method. The created amplicons are transcribed into mRNA and bind to a toehold sensor, thus activating a reporter gene.

Once this gene is translated, it produces catechol 2,3 dioxygenase which reacts with catechol and creates a colorimetric feedback. Both the transcription of the amplicons and the translation of the reporter gene are done in our homemade OnePot PURE cell-free system.