Week 9 Lab: Cell Free

Lab9

In lab this week we learned about protein purification through a demo, then we mostly worked on our final projects. Here’s some more information about mine

Final project - First DNA Twist Order

For my final project, I want to make a “hydration” checking wearable device. Originally, I wanted to sense increased sodium levels insweat but that proved to be difficult so instead I’m approximating increased hydration risk by just detecting lactate. I want this to be a cell free system to make it more compatible with a safe wearable device.

Lactate (input signal from sweat) -> Lactate Oxidase (breaks lactate down into) -> Pyruvate (byproduct not used) + H2O2 (which then activates OxyR by oxidizing it) -> OxyR (has two states starts reduced then is oxidized to become active and bind to DNA to activate transcription of PoxyS) -> PoxyS Promoter (controlled by OxyR, switches on reporter gene) -> RNA Aptamer (produced when PoxyS promoter is enabled binds to dye) -> DFHBI Dye (non-fluorescent when bound to RNA Aptamer)

All together it follows this chain: Lactate provides the biological input (increased sweat means increased need for hydration) Lactate Oxidase and H2O2 convert it into a detectable chemical signal OxyR and PoxyS act as switch RNA aptamer and dye generate a fast fluorescent output (that way the glow happens quicker than with protein translation and safer for a wearable because there are no cells)