Updated on 2021-11-18: You might found this file, which we prepared for the Judging Session, helpful to understand our goals, approaches and what have been achieved.
# Implementation of our project
As a conditionally pathogenic strainh, Candida albicans can colonize on genital/gastrointestinal mucosa without causing disease, and only in immunosuppressed hosts can C. albicans become pathogenic. Vulva vaginal inflammation caused by Candida infection is one of the most common vulva inflammation in women. However, the existing detection methods still have problems such as low accuracy in clinical testing, high cost, and long cycles in laboratory testing. So we tried to build a product for the rapid, cheap, and accurate detection of Candida albicans, which can be used in resource-limited regions as well.
We used E. coli to over-express the Bst DNA polymerase entailed in loop-mediated isothermal amplification (LAMP) reaction. Besides, we designed gene circuits with our core parts gp2 and gp5.7 to suppress the background protein translation and uplift the relative purity of Bst polymerase produced by E. coli, and by fusing Bst with various kinds of DNA binding proteins, we are hoping to reduce the cost of the detection and increase the efficiency simultaneously.
# Target groups and envision of using Candicamera
C. albicans is closely related to menstrual health risk, therefore our target group is women in general. By using a testing strip along with several reagents, the reaction can also be used for self-testing in the comfort of one’s home. Besides, Our design especially cared about women in remote and resource-limited areas where no lab conditions can be achieved and costly detection cannot be carried out either. Our product can then also act as preliminary diagnostics for urban women (especially working females) with limited time to seek out medical attention. Our test kit also has a high-cost version containing snailase to digest C. albicans cell wall more efficiently.
We left detailed documentation of our testing procedure for other labs to reference. Future teams working on C. albican detection directly access the protocol to test its efficiency or make further modifications.
- Prepare LAMP reaction system as below
- 65°C for 60-90 minutes using a thermos.
- Add 1 ul of detecting probes and incubate for 37 °C 10 mins.
- Dilute the reaction solution ten times into a 1.5ml EP tube.
- Plug the testing strip into the tube and results will be seen within 5 mins.
| 10x Bst LF Buffer<br> | 2.5ul |
|---|---|
| F3/B3/LF/LB | 0.5ul each |
| FIP/BIP | 2 ul |
| dNTP | 1 ul |
| Bst DNA polymerase Large Fragment | 1 ul |
| ddH2O | 12.5 ul |
| Template | 2 ul |
| Total | 25 ul |
But why stop here? In our integrated human practices, we were informed that fungi detection is neglected both by researchers and businesses. With simple changes made to our test probe and primers, we could develop a testing platform for multiple types of fungi. This could mean a wide spectrum of applications ranging from diagnostics to environmental fields.
# Product Form
Our product aims to provide preliminary test results for C. albicans and direct women with menstrual health risks to medical attention. Public hospitals can purchase consumables required for our test including vaginal swabs and reagents as well as the testing paper at a relatively low price. Additionally, we provided our own production methods through host bacterial expression.
# Further Engineering
Due to time limitation and the pandemic, contamination of the DNA sample in the collection process has yet to be addressed in our design. We intend to design hardware to address this issue. For instance, a protective cap could be placed on the swab to create negative pressure and therefore reduce the chance of contamination.
# Further Education
We developed our own versions of popular time-killing games to promote synthetic biology. Introducing games to education can: (i) enable future teams to use our games in education or make their own versions of education games; (ii) inspire more commitment to education in remote areas; (iii) promote STEM education for the younger age group. Collectively, these impacts may lead to a greater number of researchers and technicians in the future generation, solving the fundamental issue of insufficient professional staff in remote areas.
# Safety Considerations
As a testing kit, our product poses a little safety risk to the human body. However, the possible leakage of our chassis bacteria and amplified nucleic acid are still considered in our safety precautions:
To help resouce limited regions to carry out the detection of Candida albicans, our product entailed living bacteria which may leak into the environment during transportation and while using. We chose to apply an auxotrophy strain which can only grow on our specific culture and the users are supposed to lysate the bacteria to carry out the subsequent detection procedures which will kill the bacteria instantly.
We worried about the accidental spread of the amplified target fragment into the environment since mutations inevitably occur when these fragments are amplified. Once the mutated DNA gets into the wild-type Candida albicans, it may pose unexpected risks to the environment. So we planned to entail chemicals in our product such as Potassium Permanganate to completely destroy the bacteria as well as its nucleic acid.