Video 1 Chip Painting
In the microfluidic chip, we have amplified the nucleic acid signal of the virus. In order to show the visual result, we also need to use the Cas protein to act on it. In order to make the reading response independent of expensive laboratory infrastructure and easy to use and store, we came up with a paper-based solution.
Figure 1 The structure of the chip
Figure 2 3D structure of the chip
The chip is mainly composed of two plexiglass plates with a glass fiber membrane containing freeze-dried protein powder in between. In order to increase the diffusion of the liquid on the paper, we added hydrophobic materials on both sides of the glass fiber membrane to prevent the capillary phenomenon of the liquid between the glass. At the same time, black materials can effectively reduce the impact of scattered light and photobleaching effects.
There is a small opening in the middle of the upper plexiglass plate, which is convenient for the amplified sample to flow into the glass fiber membrane through the microtube for the next reaction. The overall chip is very small, easy to carry and store, but it is still in the laboratory stage.
Figure 3 Details of the chip
Figure 4 Mechanism in the chip
When the sample flows into the detection chip after RPA amplification, the Cas13 protein on the glass fiber membrane is activated by the existing virus sequence to cut the corresponding reporter molecule. We will freeze-dry four Cas proteins on this glass fiber membrane and equip it with four reporter molecules, so that we can realize the idea of detecting multiple viruses at the same time. The mechanism will be described in further detail in wetlab.