We aim to design a user-friendly and implemental product that is responsible and good for the world. To achieve this purpose, we need to consider these issues: The potential users and their demands; The implementation scenario of our project; The safety aspects in implementation;


After the broadly investigation and field research(More in Human Practice), we proposed our end users is Administration for Market Regulation, a government institute responsible for the food inspection. The first consideration of our end users is the responsibility and scientific knowledge in food inspection. We proposed our end users should be accountable for the food safety and have the duty in food inspection. Even though our product is easy to manipulate and could directly exhibit detection result, the manipulator is still necessary to know the requirement and rule of food inspection that stipulated by the National Standard. Our ultimate goal is to diminish the potential of foodborne disease. Consequently, we think the contaminated food should be detected in the upstream of the food circulation chain as soon as possible to prevent the further circulation. The Administration for Market Regulation inspect the food circulation in every step and they are the primary inspector that direct contact with the food sample.In addition, we proposed our end users have the demands in a fast and portable detection kit. The Administration for Market Regulation have the duty to inspect food frequently. Besides, they signify there is no such a detection kit currently and they have the demand in a fast and portable detection kit.

We supposed the hospital is one of our potential users after the conversation with Dr. Xiujuan Shen in the Suzhou NO.5 People’s Hospital. We know that because the bacteria detection process (culturing method) takes over seven days, the broad-spectrum antibiotic will first treat the diagnosed foodborne disease patients.Knowing that the hospital is accountable for patient's health, knows bacteria detection, and has the demands in a fast and portable detection kit, we supposed the hospital is one of our end users. We expected the successful implementation of our product might detect which bacteria the patient infected to have a more specific treatment rather than the use of the broad-spectrum antibiotic.


Knowing that the Administration for Market Regulation is our end users, we then participate in their food inspection routine to investigate the implementation scenario >in reality. Normally, there are 3-4 people in a group to collect the food samples from different category within a short period. Hence, there are demands in a fast and potable detection kit that could detect multiple bacteria species in the same time and generate the visible result. The features of fast, visible result and multiple bacteria detections have been performed in the project design.(More in Design) To meet the needs of a potable product, we design the prototype of a handheld product, and the size about 10cm*5cm. In the prototype, the left part is for food sample, and the visible result presented in a transparent region located in the right site.

Figure.1 the prototype of our detection kit.


Beyond the demands of a product, safety aspect is an important consideration for an implemental product. To prevent any potential leakage of the contents, first, we need to make sure our kit is impermeable. Then we need to design the suicide switch of our phage to prevent any risk when leakage happens.

In our design, to minimize the adverse effect on human health and the environment when leakage happens. We inserted our exogenous gene into the T4 genome by disrupting gp23 or gp24. Gp23 and gp24 are both essential proteins to assemble the phage head. The disruption of these proteins is detrimental to assembling the phage progeny. Thus, our phage will not produce offspring, thus posing little risk to nature and humans. To produce such phage, we used the CRISPR/Cas9 system, and we will also provide gp24 or gp23 gene on the plasmid of pCas9 for complement so that a complete phage can still be produced. We can overcome the cutting of CRISPR/Cas9 complex of pCas9 plasmid by codon optimization for gp24 on the plasmid. More in safety part